mapper.one vs Altim

mapper.one is a free, open-source field mapping app built for hikers, overlanders, and backcountry explorers. Standing on the shoulders of OpenStreetMap and the global open-data community. IMPORT YOUR MAPS Bring in routes from any source — GPX from Garmin or Strava, KML/KMZ from Google Earth or Avenza, and GeoJSON from any GIS tool. Every feature, waypoint, and track renders immediately on a full-screen map. OFFLINE-FIRST Download map tiles for any region before you leave signal. Saved tiles live in durable device storage so they survive cache pressure — your maps are there when the trail goes dark. RECORD YOUR ROUTE Hit record and mapper.one traces your path with timestamps and elevation data. Drop waypoints mid-trip with photos and notes — field markers that stay attached to the track. COMMUNITY LIBRARY Browse thousands of trails and overlanding roads contributed by the Adventure Collective and the open-data community. Filter by region, search by name, or let the app find routes near you. Download any route to your library with a single tap. SHARE WHAT YOU FIND Publish your recorded tracks to the community so others can follow in your footsteps. Open-source, open-access, community-first. Free forever. No ads. No subscriptions. No account required. Built with deep gratitude to OpenStreetMap contributors, the Leaflet project, and every surveyor and trailblazer who mapped the wild places before us.

ALTIM-O-TRON is a precision altimeter that works when nothing else does: no cell service, no Wi-Fi, no problem. It reads GPS satellites and your iPhone's barometer directly, fusing them into a smooth, accurate altitude readout wrapped in a glowing instrument panel. KNOW YOUR ALTITUDE • GPS + barometer fusion: absolute accuracy with instant response • Vertical speed, pressure altitude, and precise coordinates • Live elevation profile of your session MEASURE IT YOUR WAY Feet and meters, obviously. But also the international standards of fathoms, furlongs, smoots, and giraffes. Choose wisely. ALTITUDE INTEL A built-in database of 300+ things lets you see your altitude in real-world terms. A number is useful, but it's much more interesting to know that you're at the same height as the tip of the Eiffel Tower, Machu Picchu, a bar-headed goose crossing the Himalaya, or the world's highest ATM (fees apply) — and the intel updates as you climb. TRUE COMPASS Includes a proper compass rose with true north computed entirely on-device, plus course and ground speed. Yes, speed can be displayed in furlongs per fortnight. You're welcome. RECORD YOUR CLIMBS The session recorder captures your elevation profile with total ascent and descent — and keeps recording with your screen locked and the phone in your pocket. Export any session as a standard GPX track for your favorite mapping apps. Use it to geotag photos with the Geotag-O-Tron sister app! READ THE SKY The offline barograph logs sea-level-corrected pressure and reads the three-hour tendency. Track the weather like the sailors of old (they didn't have smartphones of course, so they had to use flip phones or Treos or something). Pressure falling fast? Maybe start heading down. ABSOLUTELY NO NETWORK Altim-O-Tron contains zero networking code. Nothing is collected, nothing is transmitted, nothing phones home. Your location never leaves your device. It works on a summit, in a slot canyon, in airplane mode, and at the bottom of Death Valley (there's altitude intel for that too). No accounts. No ads. No tracking. No masters.