If you are having problems with an app (e.g., the app not responding, not opening, closing unexpectedly or freezing, etc.) that you downloaded from the App Store, try the following tips to troubleshoot your issue:
Make sure that the app is compatible with your iOS. If not, you may want to update your device (iPad, iPhone, iPod Touch) to the latest version of iOS. You can update your device wirelessly (iOS 5 and later) OR via iTunes by connecting your device to your computer. Please read this article for further info. You may check your iOS version via Settings > General > About.
Make sure that the app is up to date: App Store > Updates
If you are having problems with all your purchased apps, you may be having an Apple ID authorization problem. To reset this, download and install a different app (that is not installed already on your device).
Restart the app you are having issues with. To do this, Double-tap the Home button to display the recent apps, then tap and hold the app until a red minus appears. Tap the red minus and then restart the app.
Reset your device by pressing and holding the Sleep/Wake button until “slide to power off” appears and slide to power off your device. When it is turned off, press the Sleep/Wake button until you see the Apple logo to turn it back on.
Reinstall the app. To do this, you need first to remove the app then reinstall it again (you may consider backing up before this step to avoid losing your data). Simply touch and hold any app icon on your screen until the application icons start to wiggle. Tap the “x” in the corner of the app you want to delete (if you don’t see the “x” check your restriction to make sure that “Deleting apps” and “Installing apps” is on). After you remove the app, go to the App Store so you can download and install the app again.
