title: How to open an app if installed through a webpage in Safari?
body: <p>We have an app, lets call it: <code>xyz_app</code> for which I have a custom URL scheme in form of <code>xyz_app://</code>.</p>
  
  <p>We are sending an email to the user.</p>
  
  <p>when he clicks on the link, he is suppose to go to the app and in case the app is not installed, our mobile website.</p>
  
  <p>so from the Link in the email, how do I make sure that if the app is not installed, that link should send the user to the mobile website instead ?</p>