When the app goes to the background a screenshot of the current app state is taken. When the app resumes that screenshot is shown for a split of a second. This is to make a visual hint to the user that the app is still running where it was before going to the background. On iOS 7 that screenshot image is used also to display the app in the multitasking experience.
For some customers this is a security concern, since that screenshot can reveal confidential app data, such as user back account numbers, usernames, private messages, etc...
A property will be exposed in the Ti.App module to avoid this from happening. The splash screen image of the app will be shown instead of a snapshot.