Briar is a messaging app designed for
activists journalists and anyone else who needs a safe easy and
robust way to communicate. Unlike traditional messaging apps Briar
doesn't rely on a central server - messages are synchronized
directly between the users' devices. If the internet's down Briar
can sync via Bluetooth or Wi-Fi keeping the information flowing in
a crisis. If the internet's up Briar can sync via the Tor network
protecting users and their relationships from surveillance.