Kavita

Kavita is a digital library server that turns a folder of manga, comics, ebooks and audiobooks into a browsable, readable collection. It groups files into series and volumes, offers a manga and comic reader with page navigation and progress tracking, supports EPUB reading and refreshes metadata from external sources, and can be extended with plugins for series information.

People use it to keep a comic pipeline organized, to read light novels and web novels on a tablet, or to give a shared family library one consistent reader.

Running the server on your own hardware keeps the collection offline and untracked, costs nothing per reader however many you add, and makes restoring a matter of copying the library folder and its database.