title: Constantly tracking user location on iOS
body: <p>I need to constantly monitor the position of an user to notify him when he gets near something interesting. Which is the correct way to achieve this?</p>
  
  <p>I have not been able to keep a timer running in the background (to periodically update user's position on the server), I also read that subscribing to significant location changes could have make me receive location updates even when the app is not running, but i can't get it happen.
  Am I on the right path? Are there any other options?</p>
  
  <p>EDIT -
  There is a requisite that i should have exposed and that is probably making me loose the focus on the real problem:</p>
  
  <ul>
  <li>Interesting "stuff" around the user has not a fixed location, so before sending a push I have to be sure that the user is <em>currently</em> in that location (of course i can assume it for n minutes).</li>
  </ul>