Just like Twitter, Rumble allows you to share message, however Rumble does not rely on any infrastructure network to work, not even the Internet. It is entirely off-the-grid and pretty unique too!
Whenever Rumble is running, it tries to connect to other rumble devices around using Bluetooth or Wifi. Rumble stores every message on a local database and forward them to its neighbour every opportunity it gets, that's how messages are distributed, they spread through the social fabric!.
Rumble allows users to create private communities. Messages from a community are only forwarded to the members. Of course you have to be invited by a member to join a community.
Rumble is free software, you can download it for free and check out the source code on github!