Ardoise is a curious tool that shows a virtual blackboard with an orange marker where you can make notes and doodles, as if it were chalk. Not only can you write on it, but also rub out what you wrote at any time. Double clicking on the runnable gives you it immediately on your desktop, in a small transparent window.
Below, in the taskbar, there is the Ardoise icon, for you to configure it and work with it. It includes a mechanism to mecanically update each time there are new versions. It has seven levels of memory. Ardoise is free and hardly consumes system resources, making it highly recommended.