Bookstash - Bookstash is a free library of curated summaries from top nonfiction books.
Kindle2Notion - Export your Kindle clippings to a Notion database
Instaread - Read or hear key takeaways of any book in minutes
Readwise - Effortlessly rediscover and organize your Kindle highlights
Book Video Club - Quick video summaries of the top business books for startups
Knotes - An efficient, beautiful Kindle highlights & notes manager