Calibre

Calibre is an open-source e-book management tool that allows users to organize, convert, and manage their e-books and digital publications. It supports a wide range of e-book formats and provides tools for editing metadata, converting formats, and syncing e-books with e-reader devices. Calibre also includes a built-in e-book viewer and editor for reading and making annotations on e-books.
Calibre is popular among e-book enthusiasts, librarians, and educators for managing digital book collections, converting formats for different devices, and organizing metadata. It is available for multiple operating systems and is continually updated with new features and improvements.s

Features

Free Features:
Calibre is entirely free and includes the following features:
E-book organization and management
Format conversion between various e-book formats
Editing and viewing e-book metadata
E-book syncing with e-reader devices