ZZZ Lifeline Mesh

Stay connected when networks fail. Nearby phones link directly over Bluetooth and relay SOS, safety check-ins and messages — no server, no account, no internet.

ZZZ Lifeline Mesh is a serverless, offline BLE mesh communication tool for disasters. Even when cell towers and networks are down, nearby devices connect directly over Bluetooth and relay (mesh) messages to one another.

Features:

• SOS and safety ("I'm OK") beacons: broadcast to nearby devices with one tap, optionally attaching your location
• One-to-one and group chat with end-to-end encryption (Ed25519 signatures + X25519 key agreement + AES-GCM)
• Store-and-forward delivery: messages reach recipients later via relays even if they are out of range now
• Pre-registered contacts: register family and friends in advance; they appear by name in a disaster, while unregistered nearby devices appear only as anonymous codes
• Public board (broadcast) to reach nearby people you have not paired with
• Multi-hop mesh relay (controlled flooding with TTL) reaches devices beyond direct Bluetooth range

No internet connection, no account, and no server required.

IMPORTANT: This app is a supplement to — not a replacement for — official emergency calls (110/119 in Japan) and government alerts.