Funny, I was just thinking this afternoon that I wished FireChat's code was open source, and was poking around to see if anybody else was tackling the "chat offline with your phones" problem, especially if anybody was playing with turning phones into "network repeaters" for however messages are being relayed.
Turns out it's much more sparse than I thought. A couple people playing with brutal bluetooth only solutions. I feel like there's a lot of possibility here, and it's probably good to explore now rather than when we really, really, need it :P
The Briar project is probably the most interesting project in this area. They recently released the first stable version [0] which includes bluetooth peer to peer messaging as a fallback if there is no internet connection available. WiFi peer to peer is also planned.
You can always count on HN to find like-minded people. Walked down the same road around 2 years ago. I think if FireChat open-sourced its mesh networking code, we could make some real progress on this. Mostly because writing a mesh networking layer is a project in itself and skipping that would go a long way.
I was thinking of using mesh networking for simple stuff at large events, like locating friends during a music festival (no cell reception).
You can check out Loud-Hailer. (Full disclosure I work there.) We enable encrypted mesh networking with a mobile app, no need to buy a device. The messaging is embedded in two different city apps we have: Columbus2GO and Providence2GO. We've created engagement points throughout the city so you can receive hyperlocal content via the BLE mesh. You can also use the apps to message friends anywhere, just need to set up permissions. We're iOS only right now, but working on Android and SDKs.
We've worked on mesh network data sync for P2P environments ( https://github.com/amark/gun ), but like others in the thread lament, vendors at the hardware level haven't been very pioneering with the tech to make it common place. Hopefully low energy Bluetooth will help that, but it has been around for years now. So I'm not keeping my fingers crossed. :(
A number of kickstarters have started to saturate this market with semi-capable meshing text-only gadgets: GoTenna, Beartooth, and Sonnet come to mind.
Turns out it's much more sparse than I thought. A couple people playing with brutal bluetooth only solutions. I feel like there's a lot of possibility here, and it's probably good to explore now rather than when we really, really, need it :P