Offline GPS LiveMap

C60 Limited

About this app

Offline GPS LiveMap is a zero-internet navigation and peer-to-peer location linking utility for the two places ordinary map apps fail: off-grid surface terrain with no cell service, and underground spaces where satellites cannot reach.

NO SIGNAL? NO PROBLEM
• Download topographic maps (contours, trails, cave entrances, roads) before you go.
• Multi-constellation satellite positioning on the surface, with your stride length and heading offset learned automatically while the fix is good.
• Backcountry trails, ski slopes, festivals, cruise ships, disaster zones, remote expeditions.

UNDERGROUND: 3D CAVE SPATIAL MAPPING
The moment satellite confidence drops (walking into a cave passage, a slot canyon or a parking garage, or when your car's Bluetooth disconnects on the ramp), the app pins a Last Known Surface Anchor and switches to automatic 3D dead reckoning:
• Depth from the barometer, Kalman-filtered: a 0.12 hPa shift is about one metre, shown in metres, feet or floor levels (B3, L2).
• Horizontal path from the step detector fused with the 9-axis rotation vector: a live 3D breadcrumb drawn on the map and in a rotatable cave view with depth profile.
• Drift correction: pass a teammate with ranging, or stand on a waypoint and tap "I'm here", and the accumulated error snaps back.

SQUAD LIVEMAP WITH NO NETWORK AT ALL
Phones with the same squad code link straight to each other using the radios already inside them:
• Nearby Connections mesh over Bluetooth, BLE, Wi-Fi Direct and Wi-Fi LAN, with store-and-forward relaying: a teammate walking back toward the entrance carries everyone's last 3D position with them.
• Wi-Fi Aware / 802.11mc RTT measures real distance from time of flight, not signal strength.
• UWB radar on supported phones: distance to the centimetre with azimuth and elevation in a directional HUD.
• Sync Beacon: every linked phone strobes its torch and screen and chirps on one shared clock. Patterns include SOS.
• Telemetry packets are under 256 bytes: position, depth, trail, battery, moving or stationary.

GUIDE ME BACK
• One tap reverses your recorded breadcrumb into prompts such as "Walk 45 steps SSW, then ascend 8.5 m to Entrance Anchor", spoken aloud.
• Pocket waypoints: double-press a volume key. Voice waypoints: hold the pin button and say "water source".
• Android 16 lock-screen Live Update: depth, distance back and nearest teammate without unlocking.
• Sessions are saved and export as GPX or CSV.

3 DAYS FREE, THEN A MONTHLY SUBSCRIPTION
Try everything free for three days. After that a monthly subscription through Google Play unlocks new trips; cancel any time in Google Play. Built-in safety rules: a trip already running is never interrupted by billing, nothing is revoked while the phone is offline, and if the subscription has lapsed an emergency unlock gives three days of full function without payment. Demo mode, saved trips, maps and settings stay free.

PRIVACY
No account, no server, no analytics, no ads. Positions travel only between the phones in your squad over local radio. Payment is handled by Google Play.

GOOD TO KNOW
Dead reckoning drifts with distance (roughly 5–8 % of the way walked; the error ring shows it) and the barometer follows the weather by a few metres an hour, so use waypoint snaps on long trips. Depth needs a barometer; UWB and Wi-Fi RTT need phones that have them. Map downloads use the public OpenTopoMap and OpenStreetMap tile servers; everything else runs offline.

Terms of use and privacy policy: https://maxfreedompollard.github.io/livemap-legal/

What’s new

Initial release of Offline GPS LiveMap.