title: GCM with PHP (Google Cloud Messaging)
body: <blockquote>
    <p><strong>Update:</strong> <a href="https://developers.google.com/cloud-messaging/" rel="noreferrer">GCM</a> is deprecated, use <a href="https://firebase.google.com/docs/cloud-messaging/" rel="noreferrer">FCM</a></p>
  </blockquote>
  
  <p>How can I integrate the new <a href="https://en.wikipedia.org/wiki/Google_Cloud_Messaging" rel="noreferrer">Google Cloud Messaging</a> in a PHP backend?</p>