Ask HN: AI tools for learning and spaced repetition

I'm looking for any products for learning new topics and that are designed for helping users retain new knowledge - eg. with spaced repetition or smart use of follow-up questions.

I can almost get chatgpt to do this, and their voice mode is great for question / answer, but it's not really setup to understand / track what you know and what your learning objectives are.

Curious to find out any positive experiences of any new tools out there.