Rated 4 out of 5 stars

I've used Chrome for some time and there I discovered the Hover Zoom extension. It proved to be NECESSARY to my browsing.
I eventually came back to Firefox because some crucial add-ons are missing in Chrome and have been using this as very fine replacement ever since.
It needs just one thing to be perfect: feedly compatibility.

This review is for a previous version of the add-on (1.5.8.1-signed). 

Improved support for Feedly and Google Reader are in 1.6.1beta1: https://addons.mozilla.org/en-US/firefox/addon/thumbnail-zoom-plus/versions/