iOS 11 crashing/freezing when apps launch
This is a bug that many ios 11.0 to 11.0.3 users are facing. On iOS 11.1 developer beta 5 however, it seems fixed. iOS 11.1 should be rolling out soon and it fixes this issue and many other battery issues. Until then, there isn't really any good solution. Hope this helps.

On iOS 11.1, if you still get the error, just back up and restore. That should work.