Some time ago I covered a trick which allows you to move tabs to the bottom in Mozilla Firefox. In that article, I used the awesome Classic Theme Restorer add-on. I was a fan of the classic Opera browser which had a fully customizable UI and I appreciate having the same ability in Firefox to be able to modify its look with the help of add-ons. One such addon is Bottom UI. It is a very interesting extension for Firefox. Let's take a look at what it offers to the end user.