Just curious for you or anyone else, what would make such an app compelling for you to use? And maybe not one that's just aimed at learning the content of this document, but if you'd like to think more broadly, an app aimed at helping you learn and retain things that you're currently interested in, studying, etc.

For these machine learning problems specifically, feel like there are so many people that would greatly benefit from having some form of spaced repetitive practice (as you mention like the adaptive Khan Academy style app), or some other easy-to-use format. I just wonder what other features people would want that would make them want to use something like this over learning with other resources (e.g., YouTube videos, reading books, etc.)