For Android
Hemisphere https://play.google.com/store/apps/details?id=com.howettl.hemisphere&hl=en
F-Secure Lokki https://play.google.com/store/apps/details?id=com.fsecure.lokki
For Iphone
Glympse – Share location with friends https://itunes.apple.com/gb/app/glympse-share-location-friends/id330316698?mt=8
Footprints http://www.footprints.net/