title: Scratch Card effect in Swift 3
body: <p>I am trying to implement a Scratch Card effect in Swift 3 for my app, I found some examples but they're on Objective C (<a href="https://stackoverflow.com/questions/20323589/show-scratch-card-effect-with-the-help-of-using-scratch-and-win-example">show scratch-card effect with the help of using scratch and win example</a>)</p>
  
  <p>In essence user swipes with finger on an image and reveals another image below their finger as they swipe. </p>
  
  <p>Any one knows how to do this in Swift 3? Any help greatly appreciated</p>