title: Service - Activity communication
body: <p>For a start, there are plenty of questions and answers about this subject, but
  my question is about what is the best practice in my specific case.</p>
  
  <p>To keep the question short, my app will have:</p>
  
  <ul>
  <li>Service to keep running after user minimize/end the app.</li>
  <li>Service runs a task every 30min looking for new info.</li>
  <li>Service shows notification when new info found.</li>
  <li>When user start/restore the app, the new info should show on the UI.</li>
  </ul>
  
  <p>I don't see the point of continuously updating the UI on a hidden activity, so what is the best solution here?</p>