Goodreads - See what your friends are reading.
LibriVox - free public domain audiobooks
GoodBooks.io - Largest curated collection of 8,500+ book recommendations.
Audible - Audible is the world’s largest provider of premium audiobooks and spoken word content.
Bookicious - Find the best new book to read with books collections for makers, founders and entrepreneurs.
Mobilism.org - A home for book lovers, app enthusiasts, and much more.