Fragment - A powerful image viewing suite with advanced metadata info
calibre - Ebook manager, viewer & converter
IrfanView - IrfanView ... one of the most popular viewers worldwide.
FBReader - FBReader is an e-book reader for various platforms. Features:
ImageGlass - You can use Image to view your digital images and photos of many different formats.
Google Play Books - Google Play Books lets you search, preview, and buy millions of books using Google Book Search.