What drew people to Sonnet was a good idea: a familiar phone app plus an external radio, working with no cellular infrastructure. Nelos is the modern app that actually delivers that today - free to start, and built on hardware that's really on sale.
What Sonnet promised can be summed up briefly: you keep a familiar phone interface, add an external radio, and a group can communicate with each other where there's no cellular infrastructure - with no per-message fee for the radio link. That's a good model, and Nelos is how you get it today: connect your phone to a small compatible radio and your team gets chat, direct messages, offline maps, device trackers and a Need Help button.
A phone is very good at being the interface: keyboard, message history, maps, and - through its own GNSS receiver - your location. What a phone can't do is send that data anywhere with no mobile network. A small radio handles exactly that part. Splitting the roles like this means you don't learn a new specialised device - you use an app much like the messaging apps you already use.
The current direction closest to Sonnet's model is a smartphone plus a LoRa mesh radio. Each person carries a small radio paired to a phone over Bluetooth; the radios talk directly to each other, and a repeater can relay for anyone out of direct range, forming a local network with no outside infrastructure. No towers, no satellite, no subscription for the radio link.
The big difference from Sonnet is that an open ecosystem sits behind it, not a single company. Many makers build compatible radio hardware, and Nelos is the app you actually use on top of it. The full background is in What Is a LoRa Mesh Radio?
Same: no subscription for the radio link; group messaging; everyone's location on an offline map; a button that alerts the group; and relaying through a repeater you add to cover a wider area (see Do You Need a LoRa Mesh Repeater?).
Different: Bluetooth rather than Wi-Fi; a native app rather than a browser; text and location rather than voice and images; and - the most practical difference - the hardware is actually on sale.
A LoRa mesh system keeps a group in touch with each other on the spot. It can't call emergency services and can't reach anyone outside the group. Range depends on terrain, with no fixed number (see Are Mesh Networks Reliable?). If you need the ability to call for rescue from a remote area, a satellite messenger or PLB is a separate layer - see LoRa Mesh vs Satellite Messenger.
Nelos is a finished, actively maintained app - not a crowdfunded prototype. You pair a compatible radio to your phone over Bluetooth, create a private team by scanning a QR code, and get messaging, everyone's latest location on a worldwide offline map, device trackers, location history, and a "Need Help" button - free to start, no account. Because compatible radios come from several manufacturers, you're not depending on one company the way Sonnet backers were.
Next steps: the off-grid communication guide for the full picture, off-grid communication devices to choose hardware, and Getting Started to set up a group. How Nelos works for a specific group is in hiking with Nelos and on the family use-case page.
Nelos brings group messaging, location sharing, and a shared group map with location updates to LoRa mesh — with no cell service, no server, and no account.
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