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

: A collection of popular science books available for free and legal download directly in the Android version's "Network Library" section.

: You can browse, purchase, and download books without leaving the app.

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

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