If you are looking for classic literature or legally free modern works, these sources are highly recommended:

: This integration is fully functional on Android and desktop platforms ( Windows, Mac, Linux ). 2. Free Legal Libraries

: High-quality, formatted editions of public domain books. 3. Adding Your Own Sources (OPDS)

: Over 75,000 free eBooks, mostly classics in the public domain.

You aren't limited to the built-in stores. You can add any website that provides an . Purchasing books on ЛитРес book store - FBReader

For Russian-language readers, FBReader has a built-in integration with , the largest digital bookstore in Russia.