Lattice Lattice

Download Lattice.

Free, with no ads, no telemetry and no tracking. The same source code and the same binary on iPhone and Android. Install it before the day you need it.

Android (Android 10 and newer)

The most direct path is to download the APK from this site and install it.

Download lattice-android.apk

Steps once the file is on your phone:

  1. Tap the downloaded file.
  2. If Android prompts for "Install unknown apps", grant your browser the permission and tap Continue.
  3. Confirm the install. The Lattice icon appears on your launcher.

The APK is signed with a stable Lattice release key. The SHA-256 fingerprint is published with each release at /downloads/lattice-android.apk.sha256, so check it before you install if integrity matters to you.

The Play Store listing is in progress. Once we're listed you'll be able to install with one tap, the same binary with less friction. The reproducible-build configuration is upstreamed too, so F-Droid can serve a third-party-verifiable build alongside our signed APK.

Android 12+ unlocks Wi-Fi Aware (NAN). Android 10–11 runs over Bluetooth LE only.

iPhone (iOS 17 and newer)

Apple doesn't let apps install themselves outside the App Store on stock iOS, so there are two ways in:

iPhone is the focus for v1. Lattice runs on iPhone but isn't iPad-optimised yet.

iOS 26 unlocks the Wi-Fi Aware framework, which Lattice uses for higher-bandwidth phone-to-phone connections in dense crowds. iOS 17–25 falls back to Bluetooth LE only and works fine, just slower when the crowd's at festival density.

A sideload route on iPhone would be nice, but the OS won't allow it for the kind of user we want to reach, and we won't pretend otherwise.

Donate.

Lattice is free. There are no ads, no data sales and no paid tier. If you want to support the work:

Source.

Lattice is open source under the MPL 2.0. The full repository goes public when v1.0 ships, once the design is stable enough to invite independent audit. Until then the signed binary is what you can verify. See build provenance and reproducibility for the SHA-256 fingerprint and the tagged-commit story.

Lattice Node — relay-only Android app.

Got a spare phone in a drawer? Install Lattice Node, leave it plugged in, and it relays for every Lattice user nearby. No chat, no contacts, no identity. Just a status panel: "I'm relaying. Yes / No." It's a different package from the messenger, so you can run both side by side.

Download lattice-node.apk

Bundle id com.lloyd.lattice.node. Same Lattice service UUID as the messenger, so it advertises into and relays for the same mesh.

Lattice Pebble — open-source firmware for £3–£20 dev boards.

Flash the Lattice Pebble firmware onto an ESP32-S3 dev board (£3 ESP32-S3-DevKitC-1, £20 Heltec WiFi LoRa V3, £40 LILYGO T-Beam Supreme, or any pin-compatible board). Plug it into a USB charger or a solar panel and walk away. The board becomes a permanent Lattice relay.

We don't make or sell hardware. We publish the firmware as a signed precompiled binary and the reference PCB design files under CC-BY-SA. Anyone can fabricate it, flash it, or sell it.

The v0.1 firmware relays over Bluetooth LE. The LoRa radio on the LoRa-equipped boards stays dormant for now and lights up in a later release.

What about Linux / Windows / macOS / desktop in general?

Not a goal. Lattice's whole point is that it uses the Bluetooth and Wi-Fi radios on a phone you carry around with you. Your laptop has those radios too, but you don't keep it in your pocket all day, so a desktop client wouldn't add any useful coverage to the mesh. We might build a thin admin or archive tool for desktops one day, but it wouldn't be a peer.