I wish there was an explanation to this. I clicked a few squares on the map until it crashed my phones browser. I tried again and selected chat from the top menu and it showed me a bunch of channels and a user list but no way to chat or do anything really.

This appears to be the same Bitchat as https://en.wikipedia.org/wiki/Bitchat

Hadn't heard of it before

Poked around for a while and it's mostly racist spam