title: Android OnBackPressed finish()?
body: <p>I'd like to know if it's a good idea to implement in all activities <code>onBackPressed()</code> the <code>finish()</code> function? Or it's not practical and not even good to do it? </p>
  
  <p>If not, what other options besides going to manifest and input the <code>SingleInstance</code> (which I think it makes the application more slow) in every activity, do I have? </p>
  
  <p>Thanks.</p>