I was using my iPhone as normal then I launched an app, and it hung up for a few seconds then back to home screen. So I launched the same app again and same problem. So I thought it may need an update as I have automatic updates turned off. Next I open App Store and same problem, it crashes and brings back to home screen. It is happening with lots of other apps as well. Facebook is working fine. I can't even go to settings. I have rebooted my iPhone various times. It is jailbroken so I have used iCleaner to clean it and it didn't help. I have run out of ideas now. I don't want to restore and lose everything. Is there any fix around this please? It's iPhone 5C on iOS 8.1.2 with Pangu jailbreak.