I added Meshtastic support to a navigation app I'm working on. Phone talks to a Meshtastic radio over BLE, pushes your coordinates out over LoRa, and you can see other people's grid positions with no cell service at all. It actually works pretty well from what I tested with a small group out in the woods.

Getting it working was a pain though. BLE docs are sparse, protobuf schemas shift between firmware releases, and there's basically nothing out there for integrating Meshtastic into your own app vs just using the official client. Lots of trial and error.

Anyone else building things on top of Meshtastic or LoRa mesh? Sensor stuff, tracking, emergency comms, whatever. What does your setup look like and how bad is the BLE flakiness on your end?