title: Tracking of registered mobile users/associates who are in defined radius of distance
body: <p>I have registered users on mobile who can be tracked on maps, once they have their mobile active with the apps. I want to track only the users who are available in a close proximity of about 1 KM (which can be defined). 
  As of now, I get result of all registered users irrespective of their distance. can you help how to track the users within the radius of choice and also users coming into that radius.</p>
  
  <p>Thanks</p>