Offline Chat is a Bluetooth chat, as well as WiFi chat. It allows users to discover other nearby users, limited to 100 meters, and create a peer-to-peer connection without any Internet or mobile data connection.
All the communication are done over WiFi direct peer-to-peer technology or Bluetooth technology.
This is not the same as a Wifi hot spot. All the communication are done over direct WiFi peer-to-peer technology. We never send any of data over the Internet. All your data is transferred between your participants.