title: How to run NSTimer in background and sleep in iOS?
body: <p>I found a lot of post in stackoverflow about <code>NSTimer</code> run in background.</p>
  
  <p>However I didn't find any solution.</p>
  
  <p>In my app , I play sound in background and I set timer to stop music when it reached that time. </p>
  
  <p>So I need to run my <code>NSTimer</code> background (mean when home button click and sleep iPhone).</p>
  
  <p>How can I do that?</p>