Enigma Code

Uses German Enigma style cipher with three wheels. Here are represented by three boxes, where you can put number from 1 to 25.
You will set the code, write message and press cipher. Then you will send new code and message to receiver.
Receiver will paste the message, set code and press decipher. That is all.

Enigma code was powerful code that lasted unbreached for a long time, when best Allies scientists were desperately trying to learn how it works.