Calibre is a mature but still kinda clunky program for managing EBooks. I used it to organise PDFs of essay and things, and sync that too my NAS so I can read it from a tablet computer.

The two I've tried are COPS and Ubooquity.

Was really easy to install via a QPKG, only hitches were:

• admin page was at a different port/address than they said [URL]:2203/admin rather than [URL]:2202/admin
• Couldn't find the address of the OPDS feed without some digging. It's: [URL]:2202/books-opds