This is amazing does exactly what it claims and has nice simple customization options, I do not understand the 1 stars at all.

Nice

It works for images on the demo page, but other images such as ones on twitter don't zoom or shrink.

this sould be the best extension, BUT. if picture/image is in some kind of frame (faceboo, for instance), image doesn't show above frame, it goes under frame. so it is visible only enlarged portion of image. i don't know is that feature or bug, but i'd like to have something like "image zoom+" or "imagus" - when i stop cursor on image, then image shows in it's whole size. AND, in every case, i'd like to see option to save that enlarged image, or at least original size (which is often smaller in page). i'll wait with uninstall, and test in other pages. but, frames "frame" me in using it.
;)

Ultra utile pour zoomer en deux sec sans quitter la page

Amazing.... I am so happy to find this add on. Very helpful. Thank you very much.