FieldNav: GPS Grid Coordinates

Know your exact grid position, save it, and walk back to it. No signal, no account, no subscription.

FieldNav is an offline grid GPS for land navigation. It reads your position in MGRS (Military Grid Reference System) and UTM (Universal Transverse Mercator), draws the real grid over the map, and keeps working past the last bar of coverage. Mark a point, build a route, record where you walked, and find your way back on a bearing.

WHO USES IT
• Search and rescue teams and first responders who pass grids over the radio
• Soldiers, veterans and land navigation students
• Wildland firefighters, forestry and survey crews
• Hunters, backcountry hikers and overlanders past cell coverage
• Airsoft, milsim, orienteering and geocaching
• HAM and SOTA operators, and anyone working off grid

COORDINATES DONE PROPERLY
• MGRS from 4 to 10 digits, with the grid drawn and labelled on the map
• UTM zone, easting and northing, correct on both sides of the equator
• Latitude and longitude in decimal, degrees and minutes, or full DMS
• Tap a readout to copy it, ready for a radio call or a message
• Type a grid or a lat/lon in by hand to save a point you were given
• Search your saved points by name or by grid
• Datums: WGS84, NAD27, OSGB36, AGD66 and ED50, each computed on its own ellipsoid instead of being approximated

IN THE FIELD
• Compass with real magnetic declination from the full WMM2025 model, so true and magnetic bearing are both right
• Navigation that survives a dead compass: without a magnetometer the rose follows your course over the ground
• GPS averaging that shows the RMS spread of the samples before you save a mark
• Waypoints in named groups, with symbols and colours
• Routes leg by leg: bearing, distance, time to go and an alert on arrival
• Track recording that keeps going with the screen off and the phone in a pocket
• Ruler for distance and azimuth, in degrees or mils
• Red night mode across the whole app, map included

OFFLINE MAPS
Download your area before you leave, or load your own MBTiles sets, and navigation works with the radio off. Online tiles come from the provider you pick, the same as in any map app.

PRIVATE BY DESIGN
No account, no ads, no tracking, no analytics. Your marks, routes and tracks stay on the phone. FieldNav has no server to send them to.

IMPORT AND EXPORT
GPX, KML and CSV, both ways. One point, a whole group or everything at once, so your work moves to a desktop map or to another device.

PAY ONCE
A single purchase unlocks everything in the app. No subscriptions, no in-app purchases, no locked tiers.

Note: the app interface is in English.

Know your grid. Trust your bearing. Find your way back.