title: Best approach for inter-app communcation without foregrounding them?
body: <p>I have been struggling on how what would be the best approach for inter-app communication without foregrounding each app.  I thought about using BroadcastReceivers to communicate between the two apps, but it appears that they must be registered in the manifest, making it difficult to bring the data to the activities.  An example would be that one app would send its status to another indicating that it is ready to start running a session.  However, I would like to keep the other app in the background while I start the session and let the user switch between apps if he or she chooses.</p>
  
  <p>Does anyone know what would be the best approach?  Basically, I would like to send data to the other app as long as the other app is running.</p>