Hidden Bar - A ultra-light MacOS utility that helps hide menu bar icons.
Imagus - The extension is intended to complement image features that (I think) is missing from Opera by...
Hocus Focus - A Mac menu bar utility that hides your inactive windows
Image Max URL - Help find larger or original versions of images, including a customizable image popup feature
Vanilla - Vanilla is a free Mac app that lets you hide icons from your menu bar.
Thumbnail Zoom Plus - The official site of the Thumbnail Zoom Plus add-on for Firefox