The military's DAGR GPS receiver costs $2,500 and weighs a pound. I built an open-source alternative that runs on your iPhone — live 10-digit MGRS coordinates, magnetic declination, waypoint navigation, 8 tactical tools, and 6 radio-ready report templates (SALUTE, 9-Line MEDEVAC, SPOT).React Native / Expo, ~15k lines of JS, fully offline, zero tracking. Location data never leaves memory.
Free on the App Store with an optional $9.99 Pro upgrade. Would love feedback on the UX, the MGRS math, or anything else — still actively developing.