title: Swift: Natively Detect if App has Crashed
body: <p>I have searched around, but have yet to find an answer that doesn't direct me towards a 3rd party service. I do not need anything intricate, just to save a value in <code>NSUserDefaults</code> so when the app opens next, I can display an alert saying the app has crashed.</p>
  
  <p>Thanks.</p>