calibre is a powerful and easy-to-use ebook manager. It is more advanced than regular ebook software, and it is free and open source.
Changelog:
New Features
Ebook polishing: Added an option to download external resources (images/stylesheets/etc.).
Conversion: Added an option under structure detection to automatically fill in the alt attribute for images with alternate text in their metadata.
Content server: Use the book title as the filename when downloading exciting content.
View downloaded metadata dialog: Added a "Previous" button to return to the previously viewed book.
Bug Fixes
Content server viewer: Fixed an issue where text at the bottom of the page was truncated on mobile browsers in non-full screen mode. Unfortunately, this means the viewer now requires a browser no older than two years.
Kindle driver: Increased the size of cover thumbnails sent to Scribe.
Kindle output: Fixed an issue where cover images containing EXIF data and not rotated were not displayed on the Kindle lock screen.
Ebook reader: Fixed an issue where ruby tags were not excluded when searching for text.
Content server viewer: Fixed a regression issue from the previous version that caused interruptions in search.
Download: https://calibre-ebook.com/en/download