title: How to use autolayout to scale view for all screen sizes?
body: <p>The main navigation view of my app uses UIButtons with background images. I'm using autolayout in IB to lay out the view.</p>
  
  <p>I want the view to look the same (or similar, just scaled appropriately) on iphone 4, 5, 6, and 6plus. I have tried using vertical and horizontal constraints but have trouble figuring out how to use the aspect ratio constraint.</p>
  
  <p>This is what the view looks like on an iphone 5.</p>
  
  <p><img src="https://i.stack.imgur.com/47tto.png" alt="view on iphone5"></p>
  
  <p>Here is what I've got so far on an iphone 6</p>
  
  <p><img src="https://i.stack.imgur.com/h38UC.png" alt="view on iphone6"></p>
  
  <p>This is what I want it to look like on an iphone 6/6plus.</p>
  
  <p><img src="https://i.stack.imgur.com/Qmu6x.png" alt="view on iphone6 - correctly laid out"></p>
  
  <p>How do I use autolayout to scale the view so that it looks the same or similar for all iphone screen sizes? </p>