MeshTalk
A Bluetooth mesh chat app for Android. Nearby phones find each other and message directly — messages hop through the mesh to reach beyond a single Bluetooth connection.
How it works
Every phone advertises and scans for other MeshTalk phones over Bluetooth Low Energy at the same time. When two phones come within range, they exchange signed, optionally encrypted packets directly — no pairing dialog, no internet connection, no account. Messages carry a hop limit and relay through other nearby phones to extend range past a single Bluetooth connection.
Public feed
A broadcast channel visible to everyone currently reachable on the mesh.
Encrypted DMs
Private messages use X25519 key exchange + AES-GCM encryption and Ed25519 signatures — only the intended recipient can read them.
Photos & files
Send a compressed photo or small file inline. Turn off receiving attachments in Settings if you'd rather not store them locally.
Runs in the background
A foreground service keeps the mesh alive, with an optional battery-optimization exemption for reliability.
Typing indicators
See "so-and-so is typing…" live in the public feed and DM threads — an ephemeral signal that's never stored or replayed.
On-device AI chat
Chat privately with Google's Gemma 4 model running entirely on your phone via LiteRT-LM — one-time download, zero connectivity needed after that, nothing ever sent over the mesh.
Bluetooth proximity finder
No GPS, no internet? Find a nearby contact by raw Bluetooth signal strength once they enable their tracking beacon in Settings.
Bluetooth radar
An opt-in "Find" tab showing everyone reachable on the mesh at once, each with an arrow and approximate distance — with an offline-cached map backdrop of your area.
Message actions
Long-press any message to copy it, react with an emoji, or edit/delete your own — all synced live to everyone else on the mesh.
Walkie-Talkie (paid)
Push-to-talk voice messages over the same offline Bluetooth mesh — hold to record, release to send. Direct-to-recipient by default, with an opt-in mesh-relay setting. Unlocked with a one-time purchase or a monthly subscription with a 3-day free trial.
Screenshots
Get it
MeshTalk is distributed two ways, since Walkie-Talkie's billing differs by channel:
Google Play
Uses Google Play Billing for the Walkie-Talkie purchase/subscription. (Play Console listing coming soon.)
Sideload (GitHub)
Download the APK directly from Releases. Walkie-Talkie purchases go through Stripe Checkout instead of Play Billing.
Source
MeshTalk is open source. The code, protocol details, and build instructions are on GitHub.