Sup is a free mobile app that shows you which friends are nearby. Don’t miss the chance to see somebody just because you didn’t know they were nearby. Sup alerts you when somebody enters your 2,000 meter radius, and gives you the option to send a ping or a chat message. It’s an app that’s actually encouraging face-to-face meet ups. And it’s better than other friend-finding apps because it doesn’t use maps — so the creep factor of seeing someone on a map has been eliminated.