Well, this is something new for me. Never had this problem before, had a reat time until 10.3, when i did the update, a few hours/day will pass and it can happen by a stuck application screen (when you go back to an app), it just opens and freeze, or when i close an app task (double tap home), and then restart the app and then the icon gets darker but the app wont open, pressing again does the same thi ng, pressing home button again will look like it closed the app but nothing was shown anyway. Unfortunetly 10.3.1 didnt fix it, and i tried full restore (with backup) from itunes and the problem persists. New iPhone 7+, never had this problems (bought when released in 2016), untill i foolishely updated to 10.3. My iPhone is a nightmare now.