Brevent is a tool that lets you force-stop (or, crash) any application from running in the background, even if it is not in the list of approved apps. You can also prevent them from starting in the first place.

If you have an Android device, you can use this tool to prevent any application from launching, even if you have not yet enabled USB debugging. It is a very useful tool for developers who need to test their apps, as well as for users who want to keep their device from launching any application that they do not want to have in the list.