Readwise - Effortlessly rediscover and organize your Kindle highlights
Four Hour Book Club - 300+ Books recommended on the Tim Ferriss Show 📚
Clippings.io - Organize the notes you make on your Kindle
Bookicious - Find the best new book to read with books collections for makers, founders and entrepreneurs.
Klib - Kindle & iBooks Highlights Manager
BookAuthority - BookAuthority collects the most recommended books on business, technology and science - as featured on CNN, Inc and Forbes