It's handy but not in real time. I was one of the first to download a few days ago and it allowed to me to see when the price began to climb quickly. But it definitely doesn't update in real time. It's now been on the same price $0.004444 for 3 days straight.

I have a feeling that it pulls from a source that someone just manually updates whenever they feel like it.

UPDATE: I just uninstalled it. First the RDD price had not changed in 3 days. Then after closing and re-opening Firefox, AVG Antivirus marked it as a questionable/unsafe add-on. Not sure what it was doing, but it was definitely using up a lot of system RAM.

AVOID THIS ADD-ON!