Glympse - Glympse is the easy way to safely share your location in realtime. No sign-up needed.
Mutt - Mutt is a small but very powerful text-based mail client for Unix operating systems.
OwnTracks - Cross-platform location sharing
Alpine - Alpine is a fast, easy to use email client that is suitable for both the inexperienced email user...
Mapple.me - Mapple.me bridges the gap between available time and availability of friends to increase social...
Mailspring - Mailspring is a mail client for Mac, Windows and Linux.