title: Timers in Sprite Kit
body: <p>I don't have experience with Sprite Kit. I was wondering is there something similar to Cocos2D <strong>schedulers</strong> in Sprite Kit ? If no, what should be used <strong>NSTimer</strong> is the only option? I guess if the only option is using  <strong>NSTimer</strong> we manually need to handle case when application is in background. Thank you.</p>