So you've coaxed someone to download your app, you've crafted an irresistibly tapworthy icon, and your lucky customer has just tapped it to launch your app. And now . . . they wait. Like all iPhone software, your app takes a second or three to load and start running. That's not exactly an eternity, but it can feel like it in the rushed context of on-the-go computing. No matter how long it takes, how fast it feels is really all that matters. You can have a big effect on that impression by carefully crafting what you show onscreen while your app fires up. Some well-timed smoke and carefully placed mirrors can make your app's startup time feel faster than it otherwise might. You'll learn more about the Jedi mind tricks for bending time with good interface design in Chapter 10. For now, consider the effect of your app's launch image.
When someone taps your icon, the iPhone OS throws a graphic onto the screen before it even fires up your app's code. This is the launch image—the placeholder screen people see while your app loads. (You bundle the launch image alongside your app's code as a full-screen 320 × 480 PNG graphic, and the iPhone displays it automatically.) It's powerfully tempting to make this image something flashy, a splash screen that dazzles and hypnotizes your audience with your remarkable Photoshop skills or the extraordinary beauty of your corporate logo. Resist that instinct and go the other way: be dull.
Use the launch image to give the impression that the app is already up and running. Apple recommends that the launch image look exactly like the app's first screen, only emptied of its content so that it's just the husk of your interface design. This approach creates the illusion that the app has started immediately—you already see its interface—and that it's already hard at work loading your content even though the code hasn't even started rolling yet. After the app finishes loading for real, it replaces the placeholder launch image with the app's first screen, as if the app has filled in the content of the previously empty screen.
Figure 7-13. The launch image should depict an empty version of the app's first screen. The launch image for the built-in Weather app (top) includes all the interface details except the content itself.
Figure 7-14. The Settings app (bottom) includes only a blank navigation bar and the pinstripe background.
Contrast this faux interface strategy with a launch image that shows a lavish splash graphic featuring an illustration or logo. The second approach feels like an ad. While a fake interface image suggests, "I'm working for you," the logo says, "I'm talking about me." The practical result is the same—with either image, it takes the same amount of time to load—but the psychological difference is pronounced. The bland interface image makes the app feel like it's loading faster. It also suggests more respect for the user's task than a marketing message, no matter how lively that message or graphic might be.
In fact, liveliness in a launch image is a problem. The more the launch image draws attention to itself, the more it draws attention to the delay while your app launches. It even makes the delay seem intentional, as if you're slowing the start of the app to show off your own logo, like the gratuitous Flash splash screens on websites from 1999. Some apps complete that outmoded effect by displaying an animation immediately after the launch image. The PayPal app shows one or two seconds of bouncing coins before it lets you do anything. The otherwise laudable Flying Without Fear app from Virgin Atlantic starts off with several seconds of title animation before launching its relaxation exercises for overcoming a flying phobia. (When you're hyperventilating at the thought of shoulder rolling through an airplane aisle at 700 mph, the last thing you want to see are production credits.)
Figure 7-15. The PayPal and Flying Without Fear apps both launch with animations that take several seconds, extending the perceived launch time.
To be fair, these apps may very well be doing some heavy work behind the scenes to get the app ready to go, and they're buying time with animations while the setup completes. As you'll learn in Chapter 10, a simple activity indicator or progress bar would do the job better. Unfortunately, the splash-screen approach makes the apps seem like they're stalling to preen about their brands. Moreover, this kind of visual drumroll underscores that you're launching the app, which of course you are, but you should instead cultivate the impression that you're switching to an app that's already running, just waiting for you to return. That trick is the topic of the next section.