Papermine - Create stunning digital booklets.
Mockupea - Mockupea is an online tool for creating 3d book mockups with a lot of features.
Pressbooks - Create books: print and ebooks
Stackoverflow '90s - Bring back '90s to Stackoverflow with this extension
Impressed Photo Books - Create a photo book in minutes. Starting at $22.
Box Shadow Generator - Generating CSS3 multilayer box-shadow has never been easier.