title: Android remote service callback pattern
body: <p>i was searching on google for possibilities to callback a client from a remote service.
  there where three major approaches:</p>
  
  <ul>
  <li>client offers AIDL the same way as the service does (bound)</li>
  <li>client listens with a broadcast receiver(onStartCommand)</li>
  <li>use of: client->createPendingResult(), service->send(), client evaluates onActivityResult()(onStartCommand)</li>
  </ul>
  
  <p>i have not found this one:</p>
  
  <p>
  client activity is launched with "singleTop" in the manifest.
  service uses context.startActivity(intent) with the answer within the intent.
  client evaluates onNewIntent(intent,..). (onStartCommand)
  </p>
  
  <p>Are there any potential problems with this approach?</p>