title: Listen to ActivityManager events?
body: <p>is it possible somehow to listen to the events of the ActivityManager, e.g. when activities are started? Does the ActivityManager send broadcasts? I havn't found anything indicating that it does.</p>
  
  <p>What I basically need to do: I want my app to launch one of my activities whenever a certain (thirdparty) app is launched/takes focus. Problem is this needs to happen before the thirdparty app is actually displayed.</p>
  
  <p>What I have tried so far as workarounds:</p>
  
  <ol>
  <li>Logcat output: I query logcat every 0.8s (filtered to show ActivityManager events only) but this eats up to many ressources</li>
  <li>getRunningTasks: Slows down the phone a lot too and is not very safe, as an activity might be running but not currently in focus</li>
  </ol>
  
  <p>Any ideas?</p>