Talk Funnel

[ This ended up being a fairly long and somewhat technical post. I edited it down as best I could, but I think it's an important topic in the iPhone world and something that has to be laid out in its entirety. I suspect it won't be of much interest unless you're an iPhone app developer, a highly technical end-user, or a masochist masquerading as a layperson. You have been warned. - Ed.]

The news dropped like a bombshell on the iPhone developer community yesterday: Apple is now allowing In App Purchasing in free applications. Hip Hip Hooray!

But wait. What does that mean?

I won’t repeat what I’ve already said in a previous post but the upshot is it’s now possible to ship a free application on the iPhone appstore then ask the customer to purchase an ‘unlock’ token once they’re done evaluating it. The common consensus (as much as what is said on blogs, mailing lists, and twitter can be considered so) in the developer community is that it’s a positive move. Marco Arment (the developer of Instapaper) called it a “… great move for both users and developers.”

The Good

With this seemingly small change in policy consumers can (finally) try out an app before they have to pay for it. No more buying an app then realizing it doesn’t work and getting stuck with a dud. The immediate effect will most likely be fewer impulse sales–which means lower short-term revenue–but in the long-term users are more likely to be happy customers instead of accidental ones.

It’ll also mean that app developers should be able to increase their asking price for well-made apps, because users will have had a chance to take it out for a test run. On the other hand, there’s no guarantee this will end up increasing per-app revenue given the low conversion ratio from free to for-pay apps. In fact, I’d strongly question the logic of $0.99 apps even bothering to offer an evaluation version. All those impulse and let’s try this purchases probably account for a more substantial portion of sales than most developers care to admit.

But the initial developer reaction seems to be positive. Most indy developers in it for the long run would rather have fewer happy customers vs. a lot of unhappy ones.

The Bad

First, let’s take a little detour and define what we actually mean by an evaluation app.

In the regular computer world (versus, you know, the iPhone Candyland) a developer creates an application then offers it to the user for evaluation in one of two possible ways:

1. Degraded mode: this is where the application has some of its features disabled, for example, no saving or only printing with a watermark. The user gets to experience what the app does, but only up to a point. How much functionality is included is up to the developer but it’s in their interest to allow as much as possible to make the sale without giving up too much.
2. Time-limited mode: this is where the application is fully functional for a limited amount of time (usually two weeks to 30 days). After that either the user buys the app or it stops working. A slight variation is where the app reverts to degraded mode when the eval clock runs out.

The main difference between a Time-Limited and a Degraded app is what the developer allows the user to experience during that period of time. That’s an important distinction because the end-user experience was noted by Apple as the main reason they initially didn’t allow In App Purchasing in free apps. The reasoning was that a user should not be told an application is free, then be forced to pay for it. But it appears that concerns for application piracy and loud complaints from developers have overridden those worries. But the problem is still valid. Hopefully Apple will make changes to the Appstore to better communicate the actual fully unlocked price to avoid end-user confusion.

There’s also a subtle issues unique to the Time-limited app on the desktop and that is what to do when the user tries to get around the evaluation restrictions — ostensibly to keep using the application in full evaluation mode ad infinitum without having to pay. The two most common methods are settings back the system clock (to make the app think the eval time hasn’t run out), or to uninstall then reinstall an app to reset the meter.

The solution to both of these problems is fairly simple: the app can write an already run token and periodically save a time-stamp in such a way that persists beyond an application getting uninstalled. Then it’s fairly easy to detect if the clock has moved back or if an app has been reinstalled.

But that’s the desktop. What about the iPhone? The problems are the same. Some users may be tempted to keep an eval app (especially a high-priced one) running. Can the clock reset trick work? Yes, it can. Most users leave their phone’s clock in its default auto-update mode so they can use their phone to keep track of time. But it’s fairly easy to reset it manually. All you have to do is run the Settings application, go under General tab and disable Set Automatically then set the clock to whatever date and time you want. The down-side to this is that so much of what you do on a typical iPhone relies on the system clock so it’s unlikely someone will be willing to put up with having a constantly skewed clock on their phone for the sake of just one application. But you never know.

What about the delete/reinstall method? On the iPhone, once an app has been deleted all associated files are also removed so there would have to be a way to save a persistent token that outlasts the app install-delete cycle. On the iPhone, unlike the Mac, no such place exists. The app developer could always save the unique device ID (UDID) of the phone on a server, but the Apple developer license explicitly forbids saving private user data off the phone. Does the UDID count as private data? It certainly is unique. We’ll have to see. But at the very least, it means each developer has to maintain server infrastructure to track this sort of thing.

So as it currently stands it’s too easy for a user to simply remove and reinstall an app or to fiddle with their clock and continue using an app in its fully-functional eval mode. I’m pretty sure this isn’t what Apple had in mind when allowing In App purchases.

That leaves Degraded mode. This means that the application the user would download from the Appstore for evaluation wouldn’t be the full version. In an earlier draft of the developer license agreement shipping this type of app was explicitly forbidden. In the newly revised version, well, it’s not so clear. In Attachment 2.4 it is clearly stated that:

2.4 You may not use the In App Purchase API to send any software updates to Your Application or otherwise add any additional executable code to Your Application. An In App Purchase item must either already exist in Your Application waiting to be unlocked, be streamed to Your Application after the purchase transaction has been completed, or be downloaded to Your Application solely as data after the purchase transaction has been completed.

This means that the full application functionality must be installed on the phone–no way to send up updated binaries. So all the code is there ready to go but a little key is needed to unlock it. On the desktop this type of app is derisively (and deservedly) called crippleware.

In other words, as of today, what Apple is allowing app developers to ship is crippleware for your iPhone. I could be wrong on this but this clearly falls under the category of Unintended Consequences.

The Ugly

The user plays with the eval app for 30 days (or so) then purchases the unlock token via In App Purchasing. The token is saved on the system so from now on the app launches in its unlocked state. But what form is that token going to take and where is it going to be stored? Given the current sandboxed architecture of the iPhone app, There are two places where an application can actually write data:

1. The filesystem under the application’s Documents folder. This can be a text file, a user preference plist, a record in a SQLite database, or a CoreData store.
2. In the keychain as a secure key/value data item.

Apple has intentionally stayed out of the business of what shape or form this add-on functionality or unlocking feature should take. It’s up to the individual developers to decide but odds are it will be one of these two methods.

Trouble is both these methods will actually make it easier for apps to get pirated.

On a regular iPhone no app can cross the sandbox line and access another app’s private data. But on a jailbroken phone no such lines exist. So a few minutes after the app is installed on a jailbroken phone, that special token can be easily extracted and plastered all over the internet. Now you don’t even need to resort to apps like Crackulous to get your free fully-functional apps.

The solution is for each individual app developer to implement tighter security around the application, by implementing secure unlock tokens, perhaps even tied to a specific handset so even if they’re removed from a single phone they won’t be usable on any other phone. But that involves knowing quite a bit about the pros and cons of cryptography and your typical iPhone app developer is not going to have the time and patience to implement anything like that.

So they’ll take the quick and expedient way–they’ll offer crippleware and save the token into a user preference plist or keychain — and hope and pray nobody bothers looking there. Or they’ll sign up with outfits like Urban Airship, iLime, or Push.IO to take care of it for them for a fee.

But this doesn’t mask the fact that with no Apple-defined standard, it’s going to be a free-for-all.

The final bit of ugliness heading our way has to do with user reviews. In the early days of the AppStore anyone could leave reviews — regardless of whether they had bought the app or not. This rendered the system useless since most of the initial write-ups consisted of, um, price-resistant customers (endearingly called freetards by developers) complaining about the price, no matter how low. It didn’t take long for Apple to clamp down on this by requiring only those who had actually purchased an app to review them. This substantially cut down on the noise and helped keep Appstore reviews an important part of the consumer decision-making process.

But now with the advent of free evaluation apps we’re going to go back to the halcyon days of price-gripes, where a user will download the free version of the app, take a look at the price for obtaining the unlock token and submit a 1-star review, complaining about, yes you got it, the price of the app. The current AppStore filter will not work since they’ve officially downloaded the app and technically count as having purchased the app.

One step forward. Two steps back. In other words, it’s going to get ugly. Again.

Unless…

You’ve been so patient. I won’t keep you waiting. Here are a few steps Apple needs to take for this eval system to work:

1. Offer a simple, official API for supporting both Time-limited and Degraded evaluations. This means associating some application metadata with each app when it’s installed and forcing Springboard (the iPhone application launcher) to honor these settings before running the application. Springboard already does this when it installs an app–that’s how the App Store application updated can tell what version you’re running vs. what’s on the store.

   To prevent the remove-reinstall workaround, there has to be a way to save some information that lives outside the sandbox and survives application removal. This can be on the phone or on a server. Again, Apple already does both these things. It saves data to the system keychain and it keeps track of what apps you’ve “bought” on the AppStore (so when you go reinstall, it knows not to charge you twice). So it would be easy for them to let the app-developer mark the application as eval, whether Time-limited (and or how long) or Degraded.

   I would even argue that anything having to do with application installation or unlocking belongs in the AppStore/OS domain, not left to individual applications. Anything having to do with In App purchasing of extra grenade-launchers, leave it up to the app.

2. Far, far more importantly (and I can’t emphasize this enough) Apple should provide a simple API for an application to verify that the current user has purchased the app. This will do far more to cut down on application piracy than allowing free evals. The app developer can periodically and at random times invoke this API and ask two simple questions: Has the current user bought this app? and When?.

   A developer would be wise to sprinkle calls to the API throughout the app. Yes, the application binary can be patched and the API call removed, but that’s a higher wall for your typical cracker to climb than simply modifying a single entry in a text file.

In the absence of a network connection, the default would be to let the application run a limited number of runs (until the user gets back to the network).

But what about the When? question? The answer would be a timestamp indicating when the user paid for the app. That piece of information is important to app-developers who currently have multiple free/pay versions of applications on the appstore (or who want to continue using that model). For these folks to move from a free/pro model to an eval/buy model means that their end users would have to obtain a new version of their application. There would have to be a way to tell whether the current user paid for the full version of the app during the pre-eval period and not force them to go through the whole purchase cycle again.

I should also emphasize that with this API the application will never have to be given access to any private user-credentials. Something like the following added to UIApplication will work wonders to ward off app piracy:

+ BOOL isAppPurchased;
+ NSDate* dateOfPurchase;

3. The last thing Apple could to do help eval/buy apps a success is implement a policy where only users who had purchased the unlock token would be allowed to post comment and reviews on the AppStore. Let’s maintain the status quo instead of taking a step back. The problem, however, is given the totally unstructured way the current In App Purchase model is implemented, there is no viable way in which an extra rocket-launcher token can be distinguished from an unlock application token.
   
   I would argue that unlocking eval applications, verifying proper ownership, and restricting access to the review system should be the responsibility of the entities that control application installation and launching–i.e., the operating system and iTunes–instead of individual developers. But in lieu of that, Apple should give developer tools to properly implement an evaluation system that welcomes legitimate users and cuts back on potential abuse.

In summary: The In App Purchase mechanism is a great system for supporting application add-ons. But it’s wholly unsuited for supporting eval applications and does nothing to fight application piracy. Having properly implemented eval apps is important to the future of this ecosystem. Apple shouldn’t leave it up to individual developers to figure out how to get there. It should be part of the core functionality of the operating system.

I agree with most everything Karl Adam says about the limitations of the Apple Push Notification Service, especially the problem with its failure to stack notifications so they’re not missed.

I posted a bug report a while back (rdar://7054632) offering a simple solution to get around this particular problem: save each incoming push payload into Messages.app as a separate entry. That way if I get a push and don’t have time to get to it I can ignore it and come back to Messages later on and retrieve it and all received Push messages are kept until I choose to get rid of them.

The entry could be in the form of a special URL link that shows the alert message, but when clicked generates the same JSON payload format as a regular push event and invokes the app in the same manner so no extra coding would be needed (OK, maybe just a little bit of code on the server to check against processing duplicate requests). It would take care of a lot of problems with push usability.

An even more pressing issue I have with Push is if you are on a WiFi network behind a bunch of firewalls and more than one NAT server. This happens often in corporations or in homes with multiple routers acting as range-extenders. In these cases pushes fail to reach you — until you get back to a 3G network.

For some people Push is doubling as a remote event timer (since Apple won’t let us access the phone’s alarm database or submit local cron tasks). This makes it really hard to issue reliable time-based alerts.

If Apple would just open up true background tasks and/or timed alerts and let the user decide whether they trust an app to let it access those services (much like location-based or push services) a lot of these hassles would go away.

Also, a European friend brought up that whereas SMS is included in most phone plans, push incurs data usage charges. Could be a hassle if you’re traveling and continue getting pushes.

Over all, I’d say push on the iPhone is a work in progress. As much as I’m intrigued and excited by its potential, I’m frustrated by its current implementation and limitations.

Popping up a modal dialog on the iPhone is a fairly straightforward process:

	modalDialogViewController *modalController = [[modalDialogViewController alloc]
            initWithNibName:@"modalDialogView" bundle:nil];
	[self presentModalViewController:modalController animated:YES];
	[modalController release];

Dismissing it then is a simple matter of the modalController invoking:

	[self dismissModalViewControllerAnimated:YES];

But what if you want to show only half a page’s worth or maybe you need the underlying view to continue being available for user viewing or interaction. Or maybe you want to show a pop-up toolbar where users are asked to choose something before continuing. You might think “Aha! I’ll just have my modal dialog view be half as tall and make the background transparent.”

Go ahead, give it a try. We’ll wait… (* … the girl from Ipanema goes walking … *)

So now you know that the standard modal dialog can only be full-screen and maintains a solid black background. What’s more you can’t interact with what’s behind it because, you know it’s modal — and modal means users shouldn’t be able to do anything else until they’re done with the front-most task (unless you’re the search box in the Contacts app in which case apparently it’s OK to be kindasortamodal).

So what we’re going to do is have a view that can be modal but takes only part of the top view, the space above it remaining visible. What’s more, you can choose to have it so tapping on the background view hides the modal view, or even go full-bore and let the background remain responsive to user input. This technically makes the view semi-modal so let’s ignore the sirens and the UI Police banging on the door and go with that.

The first thing you need is a view that has something interactive on it. The easiest way to build one is in interface builder, so go ahead and make yourself one. For the sake of expedience make it only a fraction of the screen. Here’s an example of a half-height view along with some user controls. The background is set to fully transparent. The view is connected to a UIViewController that reacts to user input:

In this case, the view is the same height as the whole screen because we want the upper portion to be see-through but not react to user input. If we wanted it to be truly interactive, we could make the view height be as tall as the actual content (i.e. half-screen) but that would make it a bit strange for the user because it would be hard to tell apart the actual content from the modal view. But hey, it’s your app. You can do what you want.

Another option is to set the background of this view black and partially transparent. That would look cool and show a nice smoky cover while we’re in modal mode… unless you’re mucking with color (like we are in this example) in which case it’s best to leave it fully transparent.

Next throw the following code in the parent UIViewController. Load up the UIViewcontroller/UIView you just created and pass the view to this routine instead of calling the standard presentModalViewController method (substitute your application delegate for MyAppDelegate):

    // Use this to show the modal view (pops-up from the bottom)`
    - (void) showModal:(UIView*) modalView
    {
    	UIWindow* mainWindow = (((MyAppDelegate*) [UIApplication sharedApplication].delegate).window);

    	CGPoint	middleCenter = modalView.center;
    	CGSize offSize = [UIScreen mainScreen].bounds.size;
    	CGPoint offScreenCenter = CGPointMake(offSize.width / 2.0, offSize.height * 1.5);
    	modalView.center = offScreenCenter; // we start off-screen
    	[mainWindow addSubview:modalView];

    	// Show it with a transition effect
    	[UIView beginAnimations:nil context:nil];
    	[UIView setAnimationDuration:0.7]; // animation duration in seconds
    	modalView.center = middleCenter;
    	[UIView commitAnimations];
    }

What this does is add your view as a top-level above the main window, effectively rendering it modal. It also uses Core Animation to move the window from offscreen bottom up until it’s fully shown. You should adjust the timing to suit your view’s actual height. I’ve found that the taller the semi-modal view, the more time you should give it to become fully visible.

Now let’s go through the hiding action. Note that we use the animation completion handler to do the actual removing of the item from the parent view and cleaning up. We also use the context parameter of the animation call (which was thoughtfully provided for exactly this sort of thing) to keep track of what view to clean up afterward:

    // Use this to slide the semi-modal view back down.
    - (void) hideModal:(UIView*) modalView
    {
    	CGSize offSize = [UIScreen mainScreen].bounds.size;
    	CGPoint offScreenCenter = CGPointMake(offSize.width / 2.0, offSize.height * 1.5);
    	[UIView beginAnimations:nil context:modalView];
    	[UIView setAnimationDuration:0.7];
    	[UIView setAnimationDelegate:self];
    	[UIView setAnimationDidStopSelector:@selector(hideModalEnded:finished:context:)];
    	modalView.center = offScreenCenter;
    	[UIView commitAnimations];
    }

    - (void) hideModalEnded:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context
    {
     UIView* modalView = (UIView *)context;
    	[modalView removeFromSuperview];
    	[modalView release];
    }

What I’m not showing you here is the way to trigger the show/hide action. That’s entirely up to you. In standard iPhone modal dialogs this is often a button in the toolbar or navigation bar. In the case of the semi-modal dialog, however, you have even more flexibility. Basically it comes down to the show/hide elements being:

• Explicit: Provide an Accept or Cancel button on your view.
• Implicit: You can simulate an action toolbar that shows and hides this way. Put a row of buttons on the view and wire it so tapping each one invokes hideModal before going on to the actual action.
• Other: Tapping anywhere else on the screen dismisses the dialog. You can do this by placing a full-screen sized view (or custom transparent button) behind your modal dialog and wiring it so it a tap-down action dismisses the dialog . For best results, try making this full-screen view black and semi-transparent (e.g. opacity=0.2). This way the user’s main view darkens so they get a sense your modal dialog is in focus but they still get to see what’s behind.

Here’s a movie of the above semi-modal view in action. It lets the user select a color then confirm or cancel the action. The modal view in this case also has interactive controls on it. As the user changes color the background image changes in real-time so they can visualize what the end-result will be like. Once they’re done they can tap the checkbox or X/cancel buttons to make the modal go away.

Play movie

The semi-modal dialog is a handy UI interaction component but it’s important to think about how to dismiss the dialog and what to allow in the rest of the visible region on the main window to avoid confusing the user. Also note that there are no restrictions on the shape or size of the overlay view as long as the background color is set to [UIColor clearColor]. You can use the same method for irregularly shaped pop-ups.

Go nuts and have fun.

Word came today that Apple’s WorldWide Developer Conference is going to be running from June 8-12 2009 in San Francisco.

Since Apple’s no longer going to be participating in MacWorld this is one of the few public conferences where Apple and its partners can make public product announcements. So now’s a good time to start floating outlandish rumors
predictions as to what’s going to be announced.

Since Apple already announced its intention to release iPhone 3.0 software around that time, a lot of products will be taking advantage of those features. One of them was access to the external USB port. The announcement demo featured a heart-monitor. My prediction is it will be totally upstaged by one of these:

One of the loudest complaints about the iPhone AppStore has been the lack of support for eval or demo applications. In the desktop world users can often download an application and use it for a period of time before deciding whether it’s worth paying for. But in the iPhone AppStore universe (where all transactions occur) there is no such support. Developers are then faced with the option of offering a lite version for free (or inexpensively) and a full version of their apps. The problem is that this still doesn’t allow the end-user to test out the full app and then choose to buy it if it fits their needs. And switching from a free to a full app involves installing an entirely independent application.

What we really need is a way to upgrade an eval app to the full version once the user decides the app is worth paying for.

Yesterday Apple publicly announced the developer release of iPhone 3.0 software (it won’t be publicly released until this Summer). To the dismay of many developers, there was — once again — no mention of support for eval applications among the 100 new features and “1000 new APIs.” So again, we are left without the option of letting users download an app, take it for a test run and then pay for it.

Or are we?

One of the features announced publicly was support for In App Purchases. This was presented as a way for users to obtain add-on levels or objects directly within games. The transaction (or more precisely, micro-transaction) still goes through the AppStore and gets charged to the same account. Despite public detractions I belive this is a Good Thing — especially since the feature can be used to legitimately support eval applications, even if the AppStore doesn’t officially support it yet.

Here’s how:

• Developer offers application for free on the app-store. This is a fully functional version (i.e. not lite or crippleware).
• User downloads and runs the application and is informed that the application is in eval mode and will stop working after a period of time.
• After the eval period (say, 1-4 weeks) the application puts up a notice indicating the eval period has expired. It can either stop working or drop into a degraded mode.
• At this point the user is given the option of performing an In App purchase of the full application.
• If user accepts, the application contacts the AppStore and purchases the add-on — which would be priced at what the full-price of the App would otherwise be. Once completed, the app downloads an add-on key indicating the app has been purchased.
• The presence of add-on indicates that the full app has been purchased and the timeout is taken out. All the application has to do each time it is launched is to look for the presence of this add-on.
• Everyone’s happy.

There’s a key assumption here — that the AppStore keeps track of already purchased In App purchases the same way it does with full applications today. In other words, if the user tries to re-download an In App purchase that they’ve already purchased with the same iTunes account, they shouldn’t be charged twice. If a user deletes the app or moves to a new phone, all they have to do is download the free version of the app, perform another In App purchase (for free this time) and off they go.

However, if this assumption is not true and In App purchases are tracked separately than full applications (or the application itself is responsible for keeping track of those transactions) then the developer will have to implement a way to track In App purchases that works across multiple app installs — most likely a simple web-server to keep track of eval vs. purchased apps. Let’s hope it doesn’t come to that (the documentation on the Store Kit is not out as of this writing and even if it was, developers under NDA won’t be able to talk about it publicly until the public release of the 3.0 software).

There are some other issues that need to be hashed out, mainly what happens if unscrupulous third-parties find out what this add-on looks like and make it available for free download? The iPhone application sandbox makes it a non-issue since only the application itself is allowed to write to its Documents directory or modify its user settings — unless the phone has been jailbroken, in which case the concerned developer may want to support more complex security (like cryptographic signing) for the add-on. Given that the AppStore DRM appears to be compromised using this technique does not significantly increase the risk of software piracy.

Another potential issue is the user who downloads the fully functional eval version, uses it for the full eval period, then deletes it, re-download and installs it so they can get another free eval period. If this is an area of concern, it can be handled through a simple web-service that keeps track of how many times the same user has installed an app. Personally, I don’t think it’s worth the hassle given that deleting an app also gets rid of all user-generated data. But that’s me.

Note also that when I’m talking about downlaoding something, I don’t mean literally downloading a chunk of code, but some sort of token that takes away the eval time limit. The whole operation can be performed very quickly once the In App transaction is completed.

I firmly believe having support for eval apps is critical for medium to high-priced applications to flourish on the AppStore. A user will hesitate to fork out a high price for a full-featured app without having the option to kick the tires beforehand. This method can easily solve the problem and let developers do eval apps as soon as the 3.0 software is officially released.

Update: Apple has since announced that free apps can not use StoreKit. This is to avoid a potential bait-and-switch situation where the consumer downloads what they think is a free app and then get hit with a fee. However, I think it’s a misguided policy. A developer who does that will quickly get down-reviewed (if they even make it out of the app-review chute). A more likely scenario would be to allow users to use an app for a limited period of time, but give them the option to unlock the app for continued use.

Another more fundamental issue, however, is whether app developers even want an eval feature. I’ve heard from several Android developers that the Android store return policy has severely impacted sales of their apps. Their argument is that returns should be based on faulty apps, not because someone found their game too hard. Presumably, enabling eval apps will cut down on a lot of impulse-then-discard purchases that go on today.

Certainly a topic worthy of further discussion.

Idea vs. Execution

Raven Zachary in a post on the O’Reilly Inside iPhone Blog raises the old idea vs. execution argument. *Sigh*. This is the same debate I’ve been hearing (and having) for the past twenty years and it keeps popping back up again.

Folks, it’s not zero-sum / either-or. It’s both. One hand holding the other. Yin and yang. It’s like saying who was more important in your creation: your mother or your father? (OK, some might say it was the Rum and Coke, but remember that’s just the catalyst.)

A lot of people bandy about the phrase “Ideas are a multiplier of execution.” As near as (Google) can tell, this phrase was popularized in a short post by Derek Sivers. What most people ignore is the conclusion he posits:

To make a business, you need to multiply the two.

In other words: I * X = success

If either I (idea) or X (execution) values are low (or zero) the outcome suffers–or stays at zero. Without a good idea, the best developers will sit around and play games or post rubbish on Twitter. Without a good implementation the best ideas will sit around till the cows come home. And the converse is true as well (bad idea/bad execution).

Architects can draw as many designs as they want, but without the builders nothing will get built. The builders can build the most fabulous walls but they won’t quite connect because they don’t have good plans.

Shall I go on? (NNNNoooo!)

So the next time you discount somebody’s idea by assigning it a value of $0, you may want to pause and give it another listen. Naturally, there are lot more ideas than implementations, but that doesn’t mean ideas are worth $0. It just means you need a knack for sifting the good from the bad. And let’s not forget good and bad are subjective valuations. If it wasn’t so, all movies and games would be instant hits.

OK, ’nuff said. I’m sure this isn’t the last time I’ll be hearing this debate again.

Product vs. Project

On a different topic, if you go by Raven’s numbers your typical developer making $125/hr working full-time will gross ~$250K a year (most developers I know work only part-time, however). If they write an app, put it on the app-store and it sells, say, 30,000 copies for the year (a conservative estimate) they would need to price it at around $10.99 in order to match the consulting rate. Write a hit (say, 100,000+/yr) and at that price, you’d be waaay ahead of the hourly rate.

The dilemma most professional iPhone developers will face is whether to take on a consulting project or spend the time working on their own product. I can tell you from personal experience, it’s pretty damn hard doing both. In a perfect world, you could do one for a while then switch to another. But it rarely works that way. While doing consulting, you’ll have to battle the constant nagging feeling that you’re actually losing money by not having your product out there and the opportunity may well slip away when someone else beats you to the market. On the other hand, while working on your product and not generating income, it’s hard to say no to someone offering you cash.

It’s a tough choice (and you should drop to your knees and kiss the ground if you’re lucky enough to be facing such a dilemma.)

Pricing

The other thing to keep in mind is that if you’re planning on writing an app for yourself and pricing it low (say, $0.99) then you’re looking at a heckuvalot of copies to make it worth not going the consulting route. iPhone developers wanting to do product development for themselves and make a good living at it might want to take Andy Finnell’s sage advice and price their apps at a more reasonable rate–something that would at least cover their costs and allow them to turn down subsequent time-intensive consulting gigs.

My personal feeling is no competent developer should be putting out $0.99 apps. They’d only be shortchanging themselves. The iPhone store is in its early stages. It’s too early to have all the shelves be stocked with apps retailers put in the discount bargain bins.

I spent all yesterday at Apple’s first iPhone Tech Talk in San Francisco (technically, Paris was first because of time differences, but we won’t quibble). After seeing the schedule of events (and having attended WWDC) my expectations for getting new technical information were pretty low.

Boy, was I wrong.

The talk itself was under NDA so I won’t go into details. But I’ll point at a couple of items in current examples and documentation that everyone should be aware of:

• If your app is using audio in any way, you’ll want to make sure you’ve read and understood the “Audio Sessions: Cooperating with Core Audio” section of the “Core Audio Overview” document (it’s part of your help document set in the SDK).

  Of special importance is making sure you declare the proper AudioSessionCategory for your app. Not doing it means that if your app uses sound (input or output) and gets interrupted — by an incoming phone call, or even by the user plugging and unplugging headphones — your app’s sound may not continue playing properly. There’s some example code in the SpeakHere example to help point the way.

  Here, by the way is what the documentation says:
  

  Ignoring Audio Session Services will not prevent your application from running, but your app may not behave the way you want it to. Never ship an iPhone or iPod touch application that uses audio without using this interface.

  You’ve been warned.

• If you’re using the accelerometer, you’ve probably seen the low-pass filter code in the docs and examples. The point of the filter is to smooth the effect of motion ‘jitter.’
  
  The thing is, the basic low-pass filter formula is — to put it mildly — non-functional (aka brain-dead). Again, I can’t talk about the specifics, but the presenter had graphs that showed how bad that formula behaves.

  Actual color graphs, I tell you!!!

  If you manage to get your hands on a sample iPhone Apple application called Touch Fighter — you’ll want to use the smoothing function there (the app was handed out in WWDC and isn’t part of the standard SDK example set).

  If you can’t find it, I suggest looking around for source code that handles the Wii remote (they have to deal with similar issues). At some point, I might post a more detailed technical article on this.

• Gesture management is still something that Apple leaves to individual developers, instead of including it in the SDK. I have a ’swipe’ detection library (but it’s only for one-finger swipes, not multi-touch). If there’s demand for it, I’ll post it up.

  But really, this should be something supported in the OS.

Most of the TechTalks are full now. If you happen to have gotten accepted, don’t skip them. If not, get on the waiting list. It’s worth it. The sessions on game development and performance tuning are massive info-dumps. Might want to take a lot of notes.

P.S. That mod-squad picture on the web site (excerpted above) features actual Apple evangelism group members strutting their stuff