This is a virtual whiteboard for schools with several aids to use at classroom. I have used it under Ubuntu and it was extremly useful as you can store/retrieve what was done and saved for further use for students.
It is a descendant of OpenSankore (abandoned) and the only way to get it is as a .deb package.
There is nothing like it in Solus packages and now that I've moved to Solus it is something missing.
Paid alternatives are expensive and are attached to some hardware making it very hard to use, particularly in public schools.
It is Open source-
How many users do you anticipate will use this software?: No idea but any school on earth could use it.
Link to source tarball/zip file: https://github.com/OpenBoard-org/OpenBoard/archive/v1.3.6.zip