Option for invisible chat is available - the messages are only shown as toast messages and are not written.
The network have to allow incoming requests. The app won't work through mobile phone connection cause mobile carriers usually prevent this kind of communication.
How to use:
1. Setup communication port in Settings. The port should be the same on all devices that communicate.
2. Input the other party IP. Your connection and current IP is shown in top area.
3. Start chat.