Bookicious - Find the best new book to read with books collections for makers, founders and entrepreneurs.
Readwise - Effortlessly rediscover and organize your Kindle highlights
Goodreads - See what your friends are reading.
Knotes - An efficient, beautiful Kindle highlights & notes manager
Bookcelerator - A curated directory of books that will make you smarter
Clippings.io - Organize the notes you make on your Kindle