Calibre Web - Calibre Web is a web app providing a clean interface for browsing, reading and downloading eBooks...
Universal Book Reader - Just like its name, Universal Book Reader is really a universal book reading application allowing you to read the eBooks from the convenience of your smartphones.
Komga - Media server for comics/mangas/BDs with API and OPDS support.
Cool Reader - Fast and small cross-platform eBook reader for desktops and handheld devices
calibre - Ebook manager, viewer & converter
iReader - iReader is one of the most accomplished ways to read the books right from your smartphones.