title: Force quit of Android App using System.exit(0) doesn't work
body: <p>when I try to quit my Android application by overwriting the function for the back-button of Android devices and "System.exit(0)", this doesn't work.</p>
  
  <p>I have an activity named "LoginActivity" and an activity named "OverviewActivity".</p>
  
  <p>When I start an intent in OverviewActivity to switch to LoginActivity, this works.</p>
  
  <pre><code>Intent changeViewIntent = new Intent(OverviewActivity.this,
              LoginActivity.class);
  startActivity(changeViewIntent);
  </code></pre>
  
  <p>Now I am in LoginActivity and there is the overwritten method:</p>
  
  <pre><code>@Override
  public void onBackPressed() {
      System.exit(0);
  }
  </code></pre>
  
  <p>But when I press the back-key (e.g. in the device simulator) the screen is blank for a millisecond and then it goes back to the OverviewActivity.</p>
  
  <p>Why is this happening? I just want to force the close when the back-key is pressed.</p>
  
  <p>History disabling for the OverviewActivity in the manifest is no option, because there are several ways to access the OverviewActivity from other activities.</p>
  
  <p>Maybe there is an idea? Android 4 is minimium requirement, so it doesn't have to work on lower versions..</p>
  
  <p>Thanks!</p>