Native FBReader is ported to Jolla phone.

From the port page: "This is an early alpha release of the SailfishOS port. It is good enough for me to read all books in my library, so I just intended to let you know it is available. No guarantees. If it crashes on importing your books or on loading a book from library, just restart.

This port to SailfishOS is sponsored by friprogramvarusyndikatet.se."