fb radar is a mobile social network application which help you find your nearby friends on Facebook without revealing your own location. Everyone of your friends can only get the "distance between you and him/her" but not your location. fb radar will also show the distance between you and him/her, when either one check in "place" with Facebook.
Enjoy the application. It will bring you a brand new experience with your friends on Facebook.
*** IMPORTANT: In order to see your Facebook friends on the application, they must also have the application installed on their mobile device. ***