Spy pen is out! Here are the controls... [Mouse]--draw with spy pen [Space bar]--switch on/off the UV light* [A]--Clear all [D]--Dev mode** [C]--Change password*** *UV light allows you to view drawings drawn by the spy pen. **Dev mode can only be used by authorized people. ***Default password is 2020 When applied on daily life... Curtis want to send a message to Raymond, but Jan is a spy. 1. Curtis use the mouse to draw the message. 2. Curtis set a new password. 3. Curtis tell Raymond the password. 4. Jan want to spy the message, but he don't know the password, so he gave up. 5. Raymond use the password to read the message. Change log: 22/5/2020—will not clear all messages and change password with a green flag click for security reasons.