From December 29th, 2015 to March 2nd, 2016, 50% user give 4-star rating, 50% user give 2-star rating. for Progress for Trello chrome extension.
It used to be useful, but right now I can't even open Options, plus the UI is kinda aged
it looks very promising from all the dev work reported on the board, but I've been unable to try it out as of yet.