Migaku
Migaku is the new project from Yoga, the original developer behind some of the tools for the old Mass Immersion Approach study method.
Some of their toolings are still really solid and useful, the Anki card exporter and mining system are probably one of my favorite to use.
I don’t know about their pathreon itself, but it’s definitely worth checking out some of their tools. Most of them should be free too.