Great add on! Thank you. I do have a suggestion though, which is the implementation of a feature that allows you to add exceptions for addresses that you want to keep opening as tabs. The thing that gave me this idea was the fact that, after downloading add on, I was unable to access the Firefox's customize page. Without the add on, it would open as a tab, and, with the add on, it just opens a blank window when you click it.

Tabbed browsing has been the bane of my browsing existence since its inception over a decade ago. Clumping every window you may ever open into one location (eggs in one basket sorta thing) was the worst design choice and even more so that it was forced on everyone. It also doesn't make sense that no matter what tab I'm on, if I open a new tab, it doesn't go to the end of the line but immediately after the tab you're currently in which totally messes with my mental map where each window is and severely reduces workflow.
In rolls in "I Hate Tabs". What a perfect name for an add-on. I will forever use this add-on. Thank you Mr. developer sir :)

Yay! Finally I can get my tabless life back on track...

When trying to "+ Add to Firefox", the following error message appears: "Download failed. Please check your connection." despite no connection issues whatsoever. (If there were connection issues, would I be able to write this review?)

I love you with all my heart. Forced into upgrading, this is the only tab free option today. You're doing gods work.