title: Prevent iOS app from deep sleeping efficiently
body: <p>I'm building an alarm clock that allows the user to play a continuous sound at a specific fire date while the app is in the foreground and the screen is locked.</p>
  
  <p><a href="https://github.com/mruegenberg/MMPDeepSleepPreventer" rel="nofollow">https://github.com/mruegenberg/MMPDeepSleepPreventer</a> is the only solution I've found to prevent my app from exiting after 10 minutes. However, this approach is causing significant battery drain.</p>
  
  <p>Are there any other approaches to this problem without draining the battery significantly? I know it is possible because there are other alarm clocks out there that do this without killing the battery and without jailbreak.</p>