Engaging screen shots can make a significant influence on a user’s perception of your app. This is your opportunity to demonstrate the capabilities, graphics, and usability of your app. When creating screen shots to be posted to the App Store, follow these general guidelines:
Make sure the content is legible and appropriate.
Consider cultural sensibilities and restrictions.
Take screen shots on the target device (not the Simulator). To do this, hold down the Power button and press the Home button. The screen shot is saved to Camera Roll.
Always remove the status bar from screen shots.
Donʼt forget to localize screen shots. Set the language for iPhone before taking screen shots by going to Settings » General » International » Language.