Block CEO Jack Dorsey has launched Bitchat, a new peer-to-peer messaging app that works entirely over Bluetooth mesh networks.

Twitter co-founder Jack Dorsey has launched a new messaging app that works without WiFi or phone service. Bitchat instead operates using a phone’s Bluetooth signal, which allows users to communicate during situations like music festivals or protests where cell service is patchy or restricted.

It connects using peer-to-peer networking instead of the internet Serial entrepreneur Jack Dorsey, who co-founded Twitter and currently acts as CEO of payments company Block, has released the source code for a peer-to-peer messaging app called bitchat that relies on Bluetooth for network connectivity.