title: Adding a UIView as a first run view only
body: <p>I would like to add a Welcome view to my app which describes the instructions etc.</p>
  
  <p>I would like this to appear only once when the app is first launched... then with subsequent launches go to my app's main view... which is a navigation controller.</p>
  
  <p>What is the best way to track launches/ implement this idea?</p>
  
  <p>Thanks.</p>