Greasemonkey Rated 4 out of 5 stars

Yes it's true, it doesn't work anymore.
But u guys, u can do this to get it back
Download Greasemonkey -
After u downloaded Greasemonkey, go to this website and install Power Twitter -
Yep, and you got ur Power Twitter back :)

This review is for a previous version of the add-on (1.52).