Glympse - Glympse is the easy way to safely share your location in realtime. No sign-up needed.
iKeyMonitor - iKeyMonitor is a mobile app for both iPhone and Android devices that with parental control capabilities and phone monitoring features.
Zenly - Zenly is a GPS tracker to locate your friends in realtime.
FlexiSPY - FlexiSPY is the original "phone spy" software - it's been on the market since 2005.
OwnTracks - Cross-platform location sharing
Companion - Never walk home alone