title: Implement chat heads like Facebook
body: <p>I want to implement chat heads like facebook does.</p>
  
  <p><img src="https://i.stack.imgur.com/Tsk6z.jpg" alt="enter image description here"></p>
  
  <p>I have tried custom notification but i haven't get any success yet.
  Please tell me if anyone have idea for implementing chat heads like this.</p>