Red Grid Link
Offline Team GPS & Map Tracker
Source: docs/images/icon_1024.png (1024x1024)
All iOS and Android sizes auto-generated in ios/Runner/Assets.xcassets/AppIcon.appiconset/ and android/app/src/main/res/mipmap-*/.
Navigation (primary), Utilities (secondary)
Track your team offline over Bluetooth. Encrypted GPS sharing, no cell needed.
Track your team anywhere -- no cell service, no internet, no accounts.
Red Grid Link turns nearby phones into a private team GPS network using Bluetooth and peer-to-peer Wi-Fi. See everyone's position on a shared map, drop waypoints, set boundaries, and coordinate -- all without cell towers or internet. Your data never leaves your devices.
Built by an active duty Army officer for the people who actually need it: search & rescue volunteers, hunting parties, backcountry hiking groups, and field training teams.
WHO IT'S FOR:
- Search & Rescue teams tracking searchers across sectors
- Hunting groups monitoring stand positions and property lines
- Backcountry hikers keeping tabs on a spread-out group
- Training teams running field exercises without military infrastructure
HOW IT WORKS: Open the app, start a session, and every teammate within Bluetooth range appears on your map. No pairing, no configuration, no internet required.
- Devices discover each other automatically over Bluetooth and peer-to-peer Wi-Fi
- Positions update every few seconds with military-grade AES-256 encryption
- Works on both iPhone and Android in the same session
- Battery-saver modes last all day (<2% per hour in Expedition mode)
- Ghost markers show last-known positions when someone moves out of range
OFFLINE MAPS: Download topographic maps before you leave service. Full USGS Topo and OpenTopoMap coverage, stored on your phone. Navigate with MGRS grid overlay -- the same military grid system used by NATO.
TEAM COORDINATION:
- Assign roles: Lead, Scout, Medic, Comms, or custom
- Share waypoints with the whole team or keep them private
- Draw boundaries and get alerted if anyone crosses them
- Drop markers for hazards, rally points, objectives, or caches
- Hands-free NATO voice callouts announce position updates
11 NAVIGATION TOOLS: Dead reckoning, two-point resection, pace counter, bearing calculator, coordinate converter (MGRS/lat-lon/DMS/UTM), range estimation, slope calculator, ETA calculator, magnetic declination, celestial navigation, and precision reference.
AFTER-ACTION REPORTS: One tap generates a PDF with your team's tracks, timeline, markers, roster, and boundary events. Share it on the spot via AirDrop or Nearby Share.
4 DISPLAY THEMES: Red Light (night vision safe), NVG Green, Day White, and Blue Force. All designed for field readability with glove-friendly controls.
PRIVACY BY DESIGN:
- No accounts, no sign-up, no login
- No cloud, no servers, no tracking, no ads
- All data stays on your device
- Session data is ephemeral -- gone when the session ends
- AES-256-GCM encryption on all team communication
- In-app purchases handled by Apple/Google only
PRICING:
- Free: All 4 modes, 2-device team sync, 1 offline map region, Red Light theme
- Pro ($3.99/mo or $29.99/yr): All themes, unlimited maps, After-Action Reports
- Pro+Link ($5.99/mo or $44.99/yr): Everything in Pro + 8-device team sync
- Lifetime ($149.99): Full Pro+Link features, one-time purchase
Subscriptions auto-renew unless cancelled at least 24 hours before the end of the current period. Payment will be charged to your Apple ID account at confirmation of purchase. Manage or cancel subscriptions in your device's Settings > Apple ID > Subscriptions.
Terms of Use: https://redgridtactical.com/terms.html Privacy Policy: https://redgridtactical.com/privacy.html
Track your team offline over Bluetooth -- no cell service needed. Encrypted GPS sharing with offline topo maps for SAR, hunting, and backcountry teams.
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Red Grid Link v1.5.1 -- critical fixes:
- Emergency Beacon: SOS button now correctly triggers the team alert and emergency overlay on the map screen.
- Field Link discovery: Scan/Join now actually initiates BLE discovery and surfaces nearby teammates.
- Hardened ECDH P-256 key exchange and stream cleanup during session teardown.
- Stability improvements and minor bug fixes.
If you experienced trouble starting a Field Link session or triggering the SOS in v1.5.0, this update resolves it.
Security and communication update:
- ECDH P-256 key exchange (per-peer encryption with forward secrecy)
- Emergency beacon with one-tap SOS and team alerts
- Tactical messaging: 8 pre-canned messages + free text
- Actual BLE Coded PHY negotiation for extended range
- Hardened stream cleanup and connection quality warnings
Extended range and navigation update:
- BLE Long Range: up to 1km range on supported devices (BLE 5.0 Coded PHY)
- Signal strength indicator for each connected teammate
- FixPhrase: share your location as 4 easy-to-remember words (~11m accuracy)
- Download OpenStreetMap or OpenTopoMap tiles for offline use
- Coordinate bar now cycles between MGRS and FixPhrase display
Team coordination update:
- Assign team roles: Lead, Scout, Medic, Comms, or custom with callsigns
- Share waypoints with your team or keep them private
- Draw boundaries -- get alerted if anyone crosses
- Drop markers for hazards, rally points, objectives, and caches
- Hands-free NATO voice callouts for position updates
- Enhanced After-Action Report with per-member tracks
- Session export/import for backup and review
- 6 annotation colors with undo and delete
Red Grid Link v1.2.2 -- navigation accuracy and usability update:
- Map tap-to-waypoint: tap any point on the map to name and save a waypoint
- Fixed MGRS grid zone bug: coordinates near band boundaries no longer shift to incorrect zones
- Dead reckoning compass mode: toggle between manual heading entry and live compass heading
- Terms of Use and Privacy Policy accessible from subscription screen
- Subscription auto-renewal disclosure in purchase flow
Red Grid Link v1.2.1 -- reliability and navigation update:
- Fixed Field Link session creation: resolved iOS Bluetooth adapter state detection that prevented session start even with Bluetooth enabled
- Field Link service initialization fix: transport state listeners now properly wired at startup
- Persistent waypoint list: save, rename, and manage multiple waypoints
- Relative bearing arrow: arrow now points the direction to turn, not just compass bearing
- Resection and Dead Reckoning tools now integrate with waypoint system
- New app icon: updated network-star design with corner brackets
- BLE transport debug logging for connection troubleshooting
- Demo mode for screenshots (Washington DC coordinates)
- 783 tests passing, 0 warnings
Red Grid Link v1.2 -- field hardening release:
- GPS Kalman filter for smoother, more accurate position tracking
- Peer HUD overlay: see distance and bearing to teammates on the map
- Step detector for accelerometer-based pace counting
- Ultra Expedition battery mode (<2%/hr for extended operations)
- Auto-reconnect with exponential backoff when peers go out of range
- Session history: review past sessions and team activity
- Offline map download UI with progress and region management
- Help & Getting Started guide accessible from Settings
- About screen with full disclaimers and Terms of Use
- Text contrast improvements across all themes (WCAG 4.5:1)
- Crash reporting (Sentry, privacy-safe -- no location data sent)
- Localization framework (English + Spanish)
- Bug fixes and stability improvements from QA testing
- 783 tests passing, 0 warnings
Red Grid Link v1.0 -- initial release:
- Live MGRS navigation with 1-meter precision
- Field Link proximity sync (BLE + peer-to-peer Wi-Fi)
- AES-256-GCM encrypted sync with ECDH key exchange
- Offline map downloads (USGS Topo + OpenTopoMap)
- Ghost markers with time-decay visualization
- 4 operational modes (SAR, Backcountry, Hunting, Training)
- 4 tactical display themes
- 11 tactical land navigation tools
- After-Action Report PDF export
- NATO phonetic voice readout
- No data collected
- No tracking
- No analytics
- All data stays on device
- Location used only when app is in foreground (and for Field Link background sync)
- Field Link shares position only with nearby peers via encrypted BLE/peer-to-peer Wi-Fi
- No server communication required for any feature
https://redgridtactical.com/privacy.html
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4+ / Everyone
Free (with Pro, Pro+Link, Team, and Lifetime in-app purchases)