I've been using spaced repeition to review highlights from books. I do it with Readwise (not affiliated, just a very happy customer). A large part of the reason I never stuck to Anki was the friction of creating, syncing, formatting the cards. This tool plugs into your services automatically so takes care of that.
Related:
Quantumn Country: A free introduction to quantum computing and quantum mechanics. Uses spaced repetition baked in directly into the article to aid comprehension and retention.