bitchat

bitchat is the experiment of the bunch. Messages hop from phone to phone over Bluetooth mesh, falling back to the Nostr network when there's a connection. It needs no servers, no accounts and no phone numbers and keeps working even when the internet is cut. That makes it genuinely useful in a crowd, a protest or a shutdown. It launched rough in 2025 with a broken identity check that let people be impersonated. Jack Dorsey moved it onto the well-tested Noise Protocol within days, which closed that hole and gave it proper authenticated encryption. What it still lacks is a full outside security audit. It has come a long way without being proven yet for anything truly sensitive.