Sleazy Fork is available in English.
Displays additional gallery information when hovering over thumbnails. Only works in thumbnail mode.
< Feedback on E-Hentai Info on Hover
Should be fixed now
Doesn't work with latest greasemonkey in Firefox 57.
Pretty much nothing works with the latest Greasemonkey since they changed/removed most of their APIs without proving backward compatible alternatives.
Consider switching to Tampermonkey or Violetmonkey.
Firefox
This script worked with Firefox somehow, until the new update, now it doesn't.