Hi, tested and works fine but could be better. The main problem with this application is, as far as I see the tabs are always displayed above the thread, which is not good when you have tabs with lots of content. I know the tabs can be truncated, but there is a better solution, look here ...
This is a similar addon, which when you add an extra tab, keeps the original thread in tab 1 and creates the custom ones besides it as 2 and 3 (like tabs in database records).
With this and the already implemented features the application would be absolutely perfect, but at the moment I sadly don't think I can use this.