title: How to detect if Facebook app is installed on iOS?
body: <p>On iOS, you can launch the Facebook app and link to a profile by opening a url like this: fb://profile/12345</p>
  
  <p>The only problem is that if the Facebook app isn't installed, nothing happens.</p>
  
  <p>Is there a way to detect if the app is installed or if the url scheme fb:// is supported?</p>
  
  <p>This would apply broadly to other apps like Twitter as well.</p>