Greasy Fork is available in English.
Support for over 70 sites! Loads manga chapter into one page in a long strip format, supports switching chapters, minimal script with no dependencies, easy to implement new sites, loads quickly and works on mobile devices through bookmarklet
< Commentaires sur Manga Loader (unmaintained)
How well would that work for manga though? At least for me there is not set time for each page. One page may have no text, while another may have a wall of information.
Slideshow
What do you think about a slideshow feature? The script would target the next image like every 10 seconds. I think i would be interesting. Cheers.