Yes there was a thread about this here a week or two ago. I downloaded it and so far I like it; it takes a couple of minutes to input the data for all your upcoming flights but then it's very easy to tag specific flights you want to watch. It's a timesaver.
The only downside I've noticed is that it doesn't track dings, you still have to watch those yourself and check them against a prepurchased fare if you have it. Also it doesn't track AirTran, but that's about the only airline I use that you can't tag flights.