title: AWS appsync and push notification
body: <p>I have built an ionic application and now I want to add the chat functionality to it.
  I was looking into different technologies that can be used to implement a chat.
  I considered using the app sync and my only concern so far, is that if I can see which users are not online at the moment of message sent event, So I can send a push notification. </p>
  
  <p>Or, if the app sync handle this out of the box and send notification as well?</p>
  
  <p>Thanks for any help</p>