calibre - Ebook manager, viewer & converter
Inoreader - Dive into your favorite content. The content reader for power users who want to save time.
FBReader - FBReader is an e-book reader for various platforms. Features:
Feedly - The content you need to accelerate your research, marketing, and sales.
Google Play Books - Google Play Books lets you search, preview, and buy millions of books using Google Book Search.
Flipboard - Your Personal Magazine. Find, follow and flip stories that change your world.