Sometimes the iPad know some damage. If ever your iPad "freeze" or not responding, there is a solution to restart without losing your data.
1. Press both the Home button (center circle) and the Sleep button Awake (top of the iPad) until the screen turns white.
2. The iPad will automatically restart and the white Apple logo should appear. Allow 30 seconds for the iPad the time to restart.
There is another way to leave a buggy application:
1. Press and hold for 6 seconds on the home button until the iPad the home screen appears