title: How to flip button in iphone sdk?
body: <p>I would like to know how buttons are flipped in the following app:</p>
  
  <p><a href="http://itunes.apple.com/app/brain-cafe-geoquiz/id334815548?mt=8" rel="nofollow noreferrer">http://itunes.apple.com/app/brain-cafe-geoquiz/id334815548?mt=8</a></p>
  
  <p>I am refering to this screen in the app:</p>
  
  <p><img src="https://i.stack.imgur.com/FGG7t.jpg" alt="enter image description here"></p>