A complete game centered around grasping the concepts of git. You can interact with it like a 'card-game' or use an integrated git terminal to learn it like on the commandline.

Another pdf ocr solution, but this one seems to be more of a 'plug-and-play' oriented one.

You simply install the command, invoke it on the cli and it does the ocr'ing and pdf/a'ing for you.
Is also required for the nextcloud ocr workflow.