Greasy Fork is available in English.
Change font, size, width and background of a work + blacklist: hide works that contain certains tags or text, have too many tags/fandoms/relations/chapters/words and other options + fullscreen reading mode + bookmarks: save the position you stopped reading a fic + number of words for each chapter and estimated reading time
< Feedback on AO3: Fic's Style, Blacklist, Bookmarks
You can disable the other features by unchecking them on the menu
Would it be possible to have just the bookmark feature as its own script?