FBReader is one of the best and most popular ebook readers. It supports various formats, is free (maybe should have started with that) doesn't hog your memory and has a pretty good selection of free books. 

Users also tout it's ease of use and the creators' continuous improvements on the app. We always pay attention to further development of an app, since no application is without bugs (whether it be a commercial or free version) and when the creators don't continue working on the app it's a sign that the app will be buggy and won't profit from users' insights. 

Among the e-book formats that are supported are ePub, fb2, plucker, Non-DRM'd version of Mobipocket and others. You can also read directly from tar,zip,gzip and bzip2 archives. It has several neat other options, like keeping the last read position of a book open, a list of last opened books etc. More options can be found on the official page of the FBreader (see link below).

Features

• many e-book formats are supported
•  direct reading from several zipped archives
• text search
• keeps last read position of book open

Official page for FBReader app

Price

Free

Scan barcode to download

(how can I use my android phone to scan barcode and download?)

FBreader android app review

We do our best to search out the best android apps for our visitors, but nothing beats a couple of pointers from other people who've used the app. Therefore, if you have experience with this app, a short comment or review about your user experience would be greatly appreciated by us and people that are interested in this app.