title: Android: Check to see if Facebook app is present on user's device
body: <p>I've kept a button which takes user to my facebook page.
  In order that the official facebook app is opened I use the following url:</p>
  
  <pre><code>fb://pages/PAGE_ID
  </code></pre>
  
  <p>instead of <a href="http://facebook.com/PAGE_ID" rel="nofollow">http://facebook.com/PAGE_ID</a></p>
  
  <p>Because in that case you get a list of browsers to open the url instead of teh facebook app.</p>
  
  <p>It works if the user has facebook app installed. However it crashes if the user doesn't have facebook app.</p>
  
  <p>Is there any way to check if the user has the facebook app?</p>