title: Android sensor listening when app in background
body: <p>Is it possible to track motion sensor events on Android continuously, even if the app is not in foreground?</p>
  
  <p>If yes - what's the drain on battery?</p>
  
  <p>A client asked if it would be possible to write an app that would initiate an action if the person "falls" - which basically means continuously listening to the motion sensor for rapid movement.</p>