title: How do I locate phones who have my app installed from inside the App? iOS 7
body: <p>I want to have my App find a locate "nearby" people.</p>
  
  <p>Sort of like how <strong>Venmo</strong> allows you to see nearby people and make payments them. I don't even know where to begin. My first though would be <strong>bluetooth</strong> but I feel that the process is sluggish and I doubt <strong>Venmo</strong> was utilizing bluetooth because I hadn't turned it on. Location seems to be my second instinct but that seems inefficient. </p>
  
  <p>Any tips or suggestions are appreciated.</p>