When comparing FBReader vs Mantano Ebook Reader Premium, the Slant community recommends FBReader for most people. In the question“What are the best eBook readers on Android?” FBReader is ranked 3rd while Mantano Ebook Reader Premium is ranked 5th. The most important reason people chose FBReader is:
FBReader, while offering many options is simple in design, with that allowing for fast use.
Ranked in these QuestionsQuestion Ranking
Pros

Pro Simple and fast
FBReader, while offering many options is simple in design, with that allowing for fast use.
Pro Cloud sync
FBReader has built in Google Drive sync for the users files, allowing them to store their eBooks online, not taking up room on their local storage.
Pro Cross-platform and open source
FBReader is a completely free cross platform eBook reader that is also open source.
Pro Built in eBook store
FBReader features an in built eBook store for users to download eBooks onto their devices through the app.
Pro Library / Bookshelf
Mantano features a library manager that appears as a bookshelf in the app.
Pro Great experience for reading
Pro Beautiful
Pro Integrates perfectly with a desktop PC
You are able to read/update/add to your library from a PC via a well designed web interface.
Cons
Con UI is bad
User interface is confusing and ugly
Con Complex and confusing app settings
Con Paid
The premium version of Mantano costs $4.99.