How do I prevent the user from closing my app?
you can override the onBackPressed method
@Override public void onBackPressed(){ Toast.MakeText(getApplicationContext(),"You Are Not Allowed to Exit the App", Toast.LENGTH_SHORT).show();}this will prevent the back button from exiting the application.
and then you will need to override the home button as well like
public boolean onKeyDown(int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_HOME) { Log.i("TEST", "Home Button"); // here you'll have to do something to prevent the button to go to the home screen return true; } return super.onKeyDown(keyCode, event);}EDIT: for new devices with android version 4.0.xx you'll have to override the recent apps button as well hope that helps you.