How to exit an Android app programmatically?

Question

I am sure this question has been asked number of times because I read a few. My client wants me to put a button into his app where users can click and exit. I have read this

Answer 1

Link this method to your quit/exit button

public void quitGame(View view) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            finishAndRemoveTask();
        } else {
            finish();
        }
    }