Phone [Q] App that prevent to exit an running app

Hello.

I am looking for a app that prevent n ser to exit a running app.

For example:

My son is often taking my android smartphone to play his favorite game during I drive the car.
Frequently it happend that he unadvertently exit/close the game app by a home or right button click.

I like to know if there any app that prevent exit an app or hat lets me controll the home or right button click.
At best it would be when there I can enable or disbale that feature by a password.

Ah, it is Android OS 4.1.

Thanks for your help!

Gerd