Red Grid MGRS
June 21, 2026 · View on GitHub
Red Grid MGRS
DAGR-Class MGRS Navigator — a $2,500 military GPS in your pocket.
The military's DAGR (AN/PSN-13) costs $2,500 and weighs a pound. Red Grid MGRS puts the same core land-navigation capability in your pocket: live 10-digit MGRS, magnetic declination, waypoints, bearing and distance, offline tactical maps, and Meshtastic mesh — all of it offline-first. No network required, no accounts, no analytics, no tracking. Location stays in memory only. Built in collaboration with active-duty and retired U.S. Army soldiers; source-available so you can read every line.
Download on the App Store · Get it on Google Play · Try the free web MGRS converter
Features
- Live MGRS coordinates — 4/6/8/10-digit precision, 1-meter resolution, free for everyone
- Magnetic declination — WMM model, auto or manual offset
- Waypoints & wayfinder — bearing and distance to any saved position
- 10 tactical tools — Back Azimuth, Dead Reckoning, Resection, Pace Count, Declination, Time-Distance-Speed, Sun & Moon, Precision selector, Elevation & Slope, Photo Geostamp
- Offline tactical maps — download OpenStreetMap / topographic tiles for your AO, dark tiles for low-vis, zero-network use
- Mission Preflight — one-glance READY / CAUTION / NOT READY check across GPS, mesh, tile coverage, permissions, and battery
- Meshtastic mesh — share your grid over LoRa via BLE and see other nodes; no cell, no internet
- External GPS — Garmin GLO, Bad Elf and other BLE receivers feed every screen
- 6 radio-ready reports — SALUTE, 9-Line MEDEVAC, SPOT, ICS 201, CASEVAC, ANGUS/CFF fire mission
- Interop & export — GPX/KML import & export, mission planning with route optimization
- NATO voice, HUD mode, grid-crossing alerts, coordinate formats, FixPhrase
- 16 languages — EN, FR, DE, ES, JA, KO, IT, NL, PT-BR, RU, ZH-Hans, ZH-Hant, TR, PL, AR, HI
| Grid & Wayfinder | Offline Maps + Mesh | Tools | Reports |
|---|---|---|---|
 |  |  |  |
| Waypoint Lists | Mesh Network | ||
 |  |
Pricing
The app is free to download. Full 10-digit MGRS (1-meter precision) is never gated.
Free: live 10-digit MGRS, map screen, 1 saved AO package, 1 theme, 3 tools (Back Azimuth, Pace Count, Declination), 3 report templates (SALUTE, 9-Line MEDEVAC, SPOT), 1 waypoint.
| Tier | Price |
|---|---|
| Monthly | $3.99/mo |
| Annual | $29.99/yr — starts with a 7-day free trial |
| Lifetime | $199.99 one-time |
Pro unlocks all 10 tools, all 6 reports, offline tactical maps, Meshtastic mesh, external GPS, mission planning, GPX/KML import & export, NATO voice readout, shake-to-speak, HUD mode, photo geostamp, grid-crossing alerts, coordinate formats, FixPhrase, all 4 themes, unlimited waypoints, and adjustable grid scale. In-app purchases are processed by Apple or Google — Red Grid MGRS never sees your payment details.
Privacy
Zero-network by design. No accounts, no ad networks, no analytics, no crash reporting, no third-party SDKs.
| Data | Collected | Stored | Transmitted |
|---|---|---|---|
| GPS location | In memory only | Never | Never |
| Waypoints (Free) | In memory, cleared on exit | Never | Never |
| Waypoint lists (Pro) | On device only | Local only | Never |
| Settings (pace / declination / theme) | On device only | Local only | Never |
| Device identifiers | Never | Never | Never |
Full policy: Privacy Policy · PRIVACY.md
Install & Develop
iOS — App Store, iOS 12+. Free, with optional Pro upgrade.
Android — Google Play, Android 7+ (API 24+). Free, with optional Pro upgrade.
Build from source — React Native 0.79.6 / Expo SDK 53. The app uses native modules (Bluetooth LE, in-app purchases, maps), so it needs a development build and cannot run in Expo Go.
git clone https://github.com/RedGridTactical/RedGridMGRS.git
cd RedGridMGRS
npm install
npx expo run:ios # or: npx expo run:android
Run the tests with npm test. Standard features work from source; Pro features require a valid purchase through Apple or Google.
Meshtastic Setup
- Flash Meshtastic firmware onto a compatible radio (Heltec V3/V4, T-Beam Supreme, RAK WisBlock, etc.).
- Close the Meshtastic app before scanning — iOS allows only one app to hold a BLE connection to a device at a time, so Red Grid can't discover the radio while the Meshtastic app is connected.
- Open Red Grid MGRS → Mesh tab → Scan → tap your radio to connect.
- Toggle Auto Share to broadcast your position over the mesh.
Supported radios: any Meshtastic device with ESP32-S3 + SX1262 LoRa at 915 MHz (US). Recommended: Heltec WiFi LoRa 32 V3/V4 or LILYGO T-Beam Supreme.
Built For
Military personnel, search-and-rescue teams, law enforcement, wildland firefighters, first responders, hunters, and backcountry navigators who depend on accurate grid coordinates in austere environments. Whether you trained on a DAGR or a lensatic compass, Red Grid MGRS speaks your language.
Ecosystem
| App | Purpose | Platform | Link |
|---|---|---|---|
| Red Grid MGRS | Solo MGRS navigator (DAGR-class) | iOS + Android | App Store · Google Play |
| Red Grid Link | Team coordination + encrypted P2P sync | iOS + Android | GitHub · App Store |
Red Grid MGRS is the solo navigator; Red Grid Link is the team coordinator (roles, boundary alerts, waypoint sharing, NATO voice callouts) over encrypted Bluetooth, free on iOS. Same MGRS engine, same precision.
The @redgrid/mgrs library (DMA TM 8358.1 compliant, zero dependencies, ~15 KB) lives in packages/mgrs. Full roadmap at redgridtactical.com/roadmap.
Support
License
MIT + Commons Clause — source-available, free for personal non-commercial use. Commercial use requires written permission.
Your phone. DAGR capability. No frills. No tracking. Source available.