Many addons and browser have tried to tackle "Too many tabs" problem, but many of them fail -- either doing too much or too little. This add-on get the job done. I likes the feature that you can not only close the tab, but also move the tab into different windows.

Just a few suggestion for developer for UI
1. The default color of close button is red, and when you hover on it, it will become deep red.
I feel the color is too busy, creating a lot of distraction, especially when you have a lot of tabs (hence a lot of close button with bold red) . My suggestion is that close and pin down button should only be displayed (in gray) when hovering on the tab, and when user move cursor to close or pin-down buttons, they will become red.
An example like this is Tab Center Redux.

2. We should be able to customize the length and width of the tabber's pop-up window.