Has your iPad ever frozen while using an app? From Apple Support
Restarting your device
- Press and hold the Sleep/Wake button for a few seconds until the red "slide to power off" slider appears, and then slide the slider.
- Press and hold the Sleep/Wake button until the Apple logo appears.
Follow these steps to reset your device
Note: Reset your device only if it is no longer responding and the steps above do not work.
- Press and hold the Sleep/Wake button and the Home button together for at least ten seconds, until the Apple logo appears.