Tableaunoir
https://tableaunoir.github.io/
Tableaunoir is an online collaborative blackboard tool with fridge magnets available in many languages. "Tableau noir" means blackboard in French. Contrary to plenty of other collaborative boards on the Internet, with Tableaunoir you can create interactive animations via the use of fridge magnets. The full documentation is available here.
Source code
Tableaunoir is written in HTML, CSS and Typescript. The source code is available here: source code
Documentation
The documentation is available here: documentation