Glympse - Glympse is the easy way to safely share your location in realtime. No sign-up needed.
OwnTracks - Cross-platform location sharing
Zenly - Zenly is a GPS tracker to locate your friends in realtime.
Foursquare - Foursquare is all about helping you find new ways to explore your city.
LockOnMe - LockOnMe is a location-sharing app, displaying targets and associated Points Of Interest on maps & fun radars.
CircleCare - Family App to Motivate Everyone