I built an app to replace the DAGR — Free instead of $2,500
Every soldier who's touched a DAGR (AN/PSN-13) knows the pain — $2,500, weighs a pound, UI from 2003, and half the time you're fighting the device instead of navigating. I built Red Grid MGRS to put the same core land nav capabilities into a phone app.
What it does:
Live 10-digit MGRS grid
Dead reckoning, two-point resection, pace count, back azimuth
Magnetic declination (auto or manual)
Waypoint lists with bearing/distance and a wayfinder arrow
6 radio report templates (SALUTE, 9-Line MEDEVAC, SPOT, CASEVAC, ICS 201, CFF)
NATO phonetic voice readout
NVG-compatible green theme
Fully offline — zero tracking, zero network calls, zero data collection. Free on the App Store, $9.99 optional Pro unlock. Open source on GitHub.
What surprised me is how little effort this actually took to build. The MGRS math, geodetic calculations, report formats — it's all public domain stuff that's been around for decades. The military is full of overpriced, outdated systems doing things a modern phone handles better. I'm hoping this sparks some genuine innovation, because the people who depend on these tools deserve better than what they're getting.
App Store: https://apps.apple.com/app/id6759629554
GitHub: https://github.com/RedGridTactical/RedGridMGRS
Android coming soon. Happy to answer questions.


Replies
Please feel free to give this article I wrote a read to learn my experience and rational for building this!
https://dev.to/redgridtactical/how-i-built-a-military-grade-gps-app-with-react-native-zero-cloud-zero-tracking-399-2klf