title: How can we make the NSTimer to run in background for my audio player in iOS
body: <p>I am making a audio player in iOS and i have made the audio player,and i am updating the duration of currently playing song using NSTimer,but the thing is that if my app goes in background the timer stops . </p>
  
  <p>Is there any way by which i can run my NSTimer in background ,in order to update the currently playing song current duration.
  How apple is running their Audio player in background?</p>
  
  <p>MPMediaPlayer and AVQueuePlayer progress slider, with time left and time elapsed.</p>