Mobilizon - A free and federated tool to get our events off Facebook

Glympse - Glympse is the easy way to safely share your location in realtime. No sign-up needed.

Upcoming.org - A simple way to share and discover interesting events

Mapple.me - Mapple.me bridges the gap between available time and availability of friends to increase social...

Happer - Meet people & participate in activities, happier together

OwnTracks - Cross-platform location sharing