title: Progressively load subviews to speed up iOS app performance
body: <p>I'm looking for a technique to progressively load in the contents of a UIViewController to make an app feel "snappier". I noticed this issue when pushing a viewcontroller onto the stack there's a noticeable delay while waiting for it to push in. The UIViewController's View has some complex subviews with transparency. I'm wondering if I create them after viewDidAppear and 'fade' them in, then the transition will appear much smoother.</p>
  
  <p>I noticed a similar effect in Apple's Trailers app. When tapping a movie in that app the detail view pushes in and the contents load after the fact. Granted part of that delay is because they are downloading the details before showing them, but it seems like they always fadein that large image whether it's been downloaded already or not. </p>
  
  <p>Has anyone had much success with this or with improving UIViewController loads in general.</p>