How to close another app in Android?

Question

I have been developing an app, and I need to close another app in my code. Does anyone know any api to call to close an app?

BTW: my app will be pre-installed.

Answer 1

You don't ever really want to close another application, due to Android activity lifecycle.
There's no benefit, and always detriment to closing another app if it's not yours, and very little benefit to closing your own.

http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle

If you know for certain that you'll never, ever need a root activity and its children (an "app"), you can stop it to free memory (it doesn't free that much), but if you do the user may restart it while it's still in cache, stopped, which can cause problems if the stopped state is restored. So this is a bad practice.