DeskPainter is a small systray tool that permits you to paint on your desktop. It can be helpful when involved in an online meeting or in-person demo; you can also just doodle away while working.
It allows you to paint the whole desktop or a user-defined area. DeskPainter supports multi-monitor setups and includes easy use via hotkeys; they are as follows F4: Show/Hide App, F9: Clear, and F10: Painting On/Off. You can create a snapshot from the current painting if needed. It lets you clear your work quickly.
DeskPainter is not overly complex, just a simple-to-use desktop painter app that is light on resources.