Question

I have a tab-based iPhone app where I want to increase the perceived start-up speed with a launch image. As defined by the iPhone HIG, the launch image is a screenshot of your app (called Default.png) that is displayed immediately and looks very similar to the app’s first screen (e.g., the screenshot of an empty table when the app displays a table first).

Now the problem with a tab-based app is that users can rearrange the order of tabs so that any of the tabs may be the first tab to show upon launch. I think I read somewhere that you can’t change the Default.png programmatically in your app, but I couldn’t find that in the HIG (and the “Clock” app seems to do exactly that – having one launch image per tab).

So, how do provide a launch image for a tab-based app?

Answer 1

There is, like you said, no way to programmatically change the Default.png (at least nothing that won’t make Apple reject your app).
This means you’d want to display a Default.png which has just a “dark border” on the bottom, without showing any of the tab bar items.
The clock app is a default app that comes with the OS, therefore it has more power than any of the App Store apps. This is just one of the reasons for Apple to include these apps in the system instead of making them an App Store app.