title: iOS Swift: How to recreate a Photos App UICollectionView Layout
body: <p>I am wondering for quiet a while now how to create the iOS Photos App layout. How can I make it so it looks like zooming in to a collection while at the same time the navigation bar shows a back button? </p>
  
  <p>Is it a new view controller which gets pushed onto a UINavigationController? And if so, how exactly do they manage to match the tiles while expanding. </p>
  
  <p>Is there maybe even a 3rd party library which lets me easily recreate such a layout?</p>
  
  <p>Hope you can help me to understand the concept of how this works.</p>