calibre - Ebook manager, viewer & converter
Google Play Books - Google Play Books lets you search, preview, and buy millions of books using Google Book Search.
ReadEra - Read book files in EPUB, PDF, DOC, DOCX, RTF, TXT, DJVU, FB2, MOBI and CHM formats.
Amazon Kindle - Amazon Kindle software lets you read ebooks on your Kindle, iPhone, iPad, PC, Mac, BlackBerry, and...
FBReader - FBReader is an e-book reader for various platforms. Features:
LibriVox - free public domain audiobooks