How can I set up thumbnail preview in Firefox?

There is a Firefox browser plugin called Imagus, which can be found at or, and it enlarges thumbnails well.


However, I want it to also enlarge images on websites like olx and allegro, and all other advertising sites, where I can hover over the ad with my mouse cursor and have the ad thumbnail enlarge in the same way as on YouTube. There is a plugin available, but it doesn't work either. I have tried various settings in the plugin, but nothing works except on YouTube. I also use Google Chrome and Opera browsers and would like a similar plugin for those browsers, but the most important thing is to have the thumbnails in Firefox enlarge for all ads.