If you intend to publish a game on the Apple App Store, you should invest an extra amount of polish to get all the details right. This includes creating an icon and splash screens for all devices, getting the bundle identifiers, bundle version, and bundle names right. If your game allows switching its orientation from landscape to portrait or vice versa, you should make sure that it does so without any side effects. You should also double-check if all the graphics are being displayed correctly on all the target devices.