In Zoom - enlarge photos and videos in Firefox / Chrome
Use mouse wheel to zoom in on images "inline" - that is - without a popup.
Hover on some image / video, press shift and use mouse wheel to zoom in and out.
Once you zoom in/out on an element, this element becomes draggable, useful in case the element is partially hidden (doesn't fit in its container).
The extension is listed on addons.mozilla.org
The extension is listed on Chrome Web Store
If you have any suggestions, please let me know: firstname.lastname@example.org or file an issue on the above github page.