khazan — Offline Chat & SOS

khazan — offline chat for workers and teams in places with no network coverage: tanks, tunnels, construction sites, warehouses, basements and remote areas.

HOW IT WORKS
Open the app and it automatically finds nearby coworkers over Bluetooth within seconds — no internet, no cellular network, no account, no phone number. Messages hop from phone to phone (mesh networking) to cover areas far beyond normal Bluetooth range.

WHAT YOU CAN SEND
- Text messages with delivery and read receipts
- Photos from camera or gallery
- Voice notes and push-to-talk walkie-talkie
- Your location — only when you choose to share it
- An urgent ring alert to a specific coworker

SOS DISTRESS CALL
An emergency button fires a loud siren, camera-flash strobe and vibration on every nearby device, repeating automatically — built to rescue a worker trapped in a tank or tunnel.

REACH FURTHER WITH INTERNET
When any internet connection is available, an additionally-encrypted copy of your messages is relayed through public relay servers to reach a distant coworker — and a single connected phone can act as a gateway for the whole group. One tap turns this off.

REAL PRIVACY
- Full end-to-end encryption (X25519 + AES-256-GCM)
- No accounts, no sign-up, no developer servers
- No ads, no tracking
- Conversations stored only on your phone
- QR identity card to add a distant coworker safely

EXTRA TOOLS
Smart call log, fast contact search and coworker-to-contact linking — all on-device.

Perfect for maintenance crews, construction, factories, mines, ships, events and off-grid trips — anywhere the network disappears but communication must not.