I have a three-year-old iPad 2. I'm still running iOS 7 on it. I've noticed a lot of app crashes lately, and they happen while using a wide variety of apps. What happens is that there's suddenly a clicking sound like the camera is being activated, and then the screen goes dark. When I press the home button, sometimes it goes to the home screen, sometimes successfully back to the app, and sometimes into a cycle of app-crash-app until I give up and reboot. Could this be the result of running automatically updated apps (re-optimized for iOS 8) on an older iOS? It seems to happen a lot, for example, with a game that came out after iOS 8 did. But it's not especially predictable. I can't reliably relate it to a single app or action. Or, is this more likely to be a hardware problem? My iPad 2 has been well cared for, but of course it is a few years old.