Jack Dorsey, the co-founder of Twitter and chief executive of Block, has released a beta version of BitChat, a messaging application that works entirely over Bluetooth mesh networks, allowing users to send encrypted messages without Wi-Fi, cellular coverage or central servers. BitChat forms ad-hoc clusters of nearby phones and relays messages from device to device, extending reach to roughly 300 metres and storing data only long enough to complete delivery. Communications are end-to-end encrypted and can be organised into public or password-protected rooms; a panic mode erases local data instantly. The iOS beta went live on Apple’s TestFlight on 6 July and hit its 10,000-tester limit within hours. Dorsey has since posted a working Android build and published a technical white paper and source code on GitHub, calling the project a personal exercise in mesh networking, encryption and “store-and-forward” protocols. Dorsey says future updates will add Wi-Fi Direct to boost range and bandwidth, while some early testers are exploring whether the mesh can relay small Bitcoin transactions offline. The software’s off-grid design echoes tools used during network blackouts and protests, positioning BitChat as a privacy-focused alternative to mainstream services such as WhatsApp.