title: start an activity without show it
body: <p>I was trying to start activity from a service without showing it to the user, keep it work in background, I was searching a lot about that, and I found two ways to do that </p>
  
  <ol>
  <li><p>by starting the activity then start the home main screen like this :
  </p>
  
  <pre><code>// this is for lunch the app
  Intent LaunchIntent = getPackageManager().getLaunchIntentForPackage("com.example.some");
  
  // this is for going back
  Intent startMain = new Intent(Intent.ACTION_MAIN);
  startMain.addCategory(Intent.CATEGORY_HOME);
  startMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
  
  // lets do it !
  startActivity(LaunchIntent);
  startActivity(startMain);
  </code></pre></li>
  </ol>
  
  <p></p>
  
  <ol start="2">
  <li><p>by putting a going back function in the activity itself, like this : </p>
  
  <pre><code>context.getActivity().moveTaskToBack(true);
  </code></pre></li>
  </ol>
  
  <p>BUT, in these two ways I have problems 
  in the first one, if the user was on another app, this operation will close his app and get him to home , more than that, some times the my activity not started but just be in the back without working i.e. if there was a song it isn't played 
  in second one, when the my activity started a black screen will appear for a second before it back to the home or previous user app </p>
  
  <p><strong>So , simply , this is what I want :
  I want a behaviour equal to : the user open my app then he press back button, but without show that the app started unless he see the background apps</strong></p>
  
  <p>how to do that ? </p>