title: how can I make the uiviewcontroller visible only once during first run of the app (e.g. tutorial)?
body: <p>I'm creating an iOS <code>swift</code> app and I want to show tutorial screen when user runs the app for the very first time. Later on, with each run of the app the tutorial should be hidden and another view controller should be visible as a starting point. So far my storyboard looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/c3vfL.png" rel="noreferrer"><img src="https://i.stack.imgur.com/c3vfL.png" alt="enter image description here"></a></p>
  
  <p>It contains two screens of tutorial (1st and last) and tab bar (which is a main window of my app). </p>
  
  <p>As for now, in storyboard I chose the tab bar to be an initial view controller:</p>
  
  <p><a href="https://i.stack.imgur.com/hCOs2.png" rel="noreferrer"><img src="https://i.stack.imgur.com/hCOs2.png" alt="enter image description here"></a></p>
  
  <p>And with that approach the tutorial screen is never seen. How can I show it only once on first launch app and then skip it each time user opens the app?</p>