Rated 4 out of 5 stars

I tried this addon and also the "Hide GUI Bars" addon. The latter one seems to have additional features along with the tab bar hiding. You can configure what bar you want to hide.
"Hide Tabbar" gave me just what I wanted, but "Hide GUI Bars" gave me more than what I wanted!

This review is for a previous version of the add-on (0.7.3).