I had Readera Premium purchased 3 years ago when I wasn’t aware of really great free softwares’ existence. I had bought it because of it’s simple interface and thought it could help me with OPDS (auto sync between devices or other apps), but it didn’t help me other than by just being simple. That’s why I am currently hosting my own OPDS server (Kavita) to sync my progress and read from it’s web interface and Librera app (really powerful and open source). I am thinking of moving to Calibre Web from Kavita because of ease of uploading books. You can try Librera which is a really great and powerful pdf/book viewer/reader with/without OPDS.
I had Readera Premium purchased 3 years ago when I wasn’t aware of really great free softwares’ existence. I had bought it because of it’s simple interface and thought it could help me with OPDS (auto sync between devices or other apps), but it didn’t help me other than by just being simple. That’s why I am currently hosting my own OPDS server (Kavita) to sync my progress and read from it’s web interface and Librera app (really powerful and open source). I am thinking of moving to Calibre Web from Kavita because of ease of uploading books. You can try Librera which is a really great and powerful pdf/book viewer/reader with/without OPDS.