iPhone 5 Quick Tip: How to add letterboxing back to your iOS 6 app

So you've removed letterboxing from your iPhone 5 app by adding a Default-568h@2x.png launch image. And there was much rejoicing.

Except now all of your layouts are messed up, and you're supposed to push an app update through to the store tomorrow. So you delete the Default-568h@2x.png launch image and...nothing. Your app still seems to be running in full-screen mode. What's the deal?

It seems to be a bug, but there is a workaround. Here are the steps that I went through to re-enable letterboxing in XCode:

1. Remove the Default-568h@2x.png launch image
2. Run a "Clean Build Folder" (⌥⇧⌘K)
3. Uninstall the app from your device/simulator
4. Build and run the app

It's not immediately clear to me why you have to jump through so many hoops -- it might be that XCode is caching an intermediate version of the image resource in the build folder, and the device/simulator is simultaneously caching a version of this image in memory or on disk.

I'll update if I get more information.