ReadEra

eBook readers are not all that rare on Android, and, in fact, there is a large number of apps that can do this task. The only difference is the interface, the features implemented, and the number of formats supported.
 
ReadEra is designed to read pretty much all of the major eBook formats, including PDF, EPUB, WORD (DOC, DOCX, RTF), MOBI, FB2, DJVU, TXT, and CHM. The application is completely free, and people are not going to be bothered by ads or any other intrusions.
 
The app also comes with a comprehensive library function that organizes all the books on your device and has support for navigation tools such as a table of contents, footnotes, fonts, and much more.