title: Custom URL to launch Facebook Messenger on iOS
body: <p>How can I launch FaceBook Messenger (if installed) with a compose Windows to a specific FB ID.</p>
  
  <p>If messenger is not installed, can we launch FaceBook app and have the compose Windows open to a specific FB ID.</p>
  
  <p>In the rare instance if no Facebook apps are installed, can we launch mobile Safari with the compose window?</p>