Solid Explorer - Solid Explorer is a powerful Android file manager featuring access to most popular cloud storages, root access and easy extensibility.
calibre - Ebook manager, viewer & converter
Amaze File Manager - Free and open-source Android file manager with no ads.
FBReader - FBReader is an e-book reader for various platforms. Features:
Total Commander - A Shareware file manager for Windows® 95/98/ME/NT/2000/XP/Vista/7, and Windows® 3.1.
Google Play Books - Google Play Books lets you search, preview, and buy millions of books using Google Book Search.