This app sends messages over local network therefore no internet is required.
But remember that to send messages to another user he must also be connected to the same network as yours.
You can join a chat or host a chat.
If you host a chat your host name will appear on the top in the next page,
others need to type that name in order to join your chat room.
There is no limit on how many people can join a chat room(recommended less than 10).