Most productivity tools like Notion or Obsidian are great for storing information, but they re terrible for learning it. I call it "The Blank Canvas Problem" you spend 3 hours setting up a database and 0 hours actually studying.
I built retenir.app to be a "Study Engine" instead. You drop the PDF, and the agents do the setup for you so you can go straight into active testing.
What feature would make you finally delete your "Study Notes" folder in Notion?
The agentic study operating system. This not only reads your notes, but plans your studies. Makes you retain and apply concepts on a deeper level. Automatically schedules your practice. Has a agent you can ask to do anything related to studying.