calibre - Ebook manager, viewer & converter
NeeView - Display two images simultaneously
Apple Books - The all-new Apple Books has been redesigned to make finding, reading, and listening to books a beautiful, effortless experience on iPhone and iPad.
FBReader - FBReader is an e-book reader for various platforms. Features:
OverDRIVE - Make workspaces and sites automatically from Google Drive
YACReader - Download YACReader for your platform. Windows, Linux, MacOSX. And enjoy you comic books cbr cbz with the best comic reader.