title: Background app to listen to Drag gestures
body: <p>I need to register a broadcast receiver that will tell me any kind of <code>Drag</code> events throughout the system. My app will run at background and perform any task if any kind of <code>Drag</code> event happens even any other app is running in the foreground. Is it possible? Any idea on how can I do it?</p>
  
  <p><strong>Updates:</strong> Do not think I'm going to make keylogger. My app will be visible but will run in background. And all I want is simply to detect Drag events (drag to left, drag to right, drag to up and drag to down).
  I'll accept any answer if you can tell me about how can I display 4 buttons those are permant, on top of any other apps because this can also serve me what I want. </p>