Shown HN: Non intrusive location sharing

Having had this idea before both Apple and Google released Find My Friends and Latitude, respectively, I thought it would still be an interesting experiment to release this simple location sharing app now to see if it catches any traction. While I feel totally comfortable using services such as Latitude to share my location, most of my friends find it far too intrusive. This app tries to bridge the gap by providing the same service but leaving the user 100% in control of who sees their locaiton. What do you think?