title: Positioning Button over Image
body: <p>I have a full screen ImageView (margins constraints) with an Image in "Aspect Fit Mode" and I need to have a button to be over a specific part of that image on all devices. </p>
  
  <p>I have tried to put constraints in different ways, but without any good result.</p>
  
  <p>I hope someone could help me.</p>
  
  <p>Here you can find a screenshot of what I want: </p>
  
  <p><a href="https://i.stack.imgur.com/cMTyk.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cMTyk.png" alt="https://www.dropbox.com/s/krl5rp47w2rxl0g/Schermata%202015-09-12%20alle%2015.15.43.png?dl=0"></a></p>
  
  <p>The yellow block is the button and I want it to be over the shoulder for any screen size.</p>
  
  <p>This is iOS 8.</p>