title: swift - Delay a spawn function using NSTimer
body: <p>I'm looking to integrate some delayed functions into my game, currently I'm working on putting a 5 second delay on calling my first function as in this time period the game goes through a countdown to get the player ready.</p>
  
  <p>Currently my countdown is displayed but the game is in full swing in the background.  I've got one function I'd like to delay for 5 seconds but I'm also thinking of using the same method to incorporate other objects later in the game to boost difficulty.</p>
  
  <p>The call I'm looking to delay is <code>moving.addChild(crows)</code></p>
  
  <p>If anyone can show me how to build that would be great as I've been unable to find on site (unless I've missed it).</p>