You can set how many minutes, and or how many hours until your device shuts down, and you can only stop it by pressing the cancel button in the app -- exiting or killing the app will not stop the timer.
Make sure you allow persistent root access, or instead of shutting down you will get a prompt from SU asking for access.
Email me about bugs or issues rating please! Remember not to 1 star me if your device isn't rooted!
This app has access to :