Bridgefy

Bridgefy keeps people connected when Internet is unavailable.

It can be used for a variety of apps. Ride hailing apps like Uber, messaging apps and also gaming apps.

Direct contact: Direct communication between devices, up to 330 feet.

Mesh networking: Messages can be delivered over larger distances through intermediary devices.

Broadcast: Messages spread out to all nearby users.

The bridgefy SDK works for both Andriod and IOS. The site also contains information on how you can make your Apps work with bridfegy.

SDK's like this are needed in places with poor internet connection.

Copied text in quotes from Bridgefy.com