Goodreads - See what your friends are reading.
Layout by Instagram - Combine multiple photos into a single image
LibraryThing - A home for your books.
Likecreeper - Randomly hit like on a friend's horrifyingly old Instagram
BookAuthority - BookAuthority collects the most recommended books on business, technology and science - as featured on CNN, Inc and Forbes
Nine by #2015bestnine - Meet Instagrammers through your best 9 photos on Instagram