This messenger is very self explanatory. Press the message icon in the corner. You can either type their username or their short key. Then type what you would like to say. As long as they have the project open, they will see the message.
Artwork: Me Encrypter/Decrypter: Someone else who I can't remember (sorry) CHANGE LOG: 0.1: Unreleased beta 0.2: Launch 0.3: Sound added when messages are received
