Rated 5 out of 5 stars
I created an account specifically to rate this app and to tell the dev how awesome he is. The lack of this addon has been a major gap in Seamonkey's usability until now.
Thankyou dev! Although this addon is quite basic and lacks indents for child tabs, it's still a wonderfully useful extension and might be the catalyst to make me switch back to SM from Pale Moon.
I really hope the dev continues to maintain this extension and adds features like indents for children and... that's about it! It's no Tree Style Tab, but it's a very welcome addition to the Seamonkey ecosystem.