Sleazy Fork is available in English.
Loads manga chapter into one page in a long strip format, supports switching chapters and works for a variety of sites, minimal script with no dependencies, easy to implement new sites, loads quickly and works on mobile devices through bookmarklet
< Opiniones de Manga Loader NSFW (unmaintained)
Could you add a feature for "auto enlarge/shrink image to client area" ?
Explain: every manga has different image sizes, with this feature we don't need to adjust zoom for every manga. Just enable this feature and use w/s key to goto next/prev page. It's super effective. :D