Roulette Winner Pro seems to have been discontinued as its developer's domain is now for sale. As far as I could see, the tool can still be downloaded from unofficial sources on the Internet, but unfortunately, you won't be able to purchase a license for it, no matter how much you try.
As an alternative, I recommend checking out the http://roulettegeek.com/ website, which also promises to offer a winning strategy for online roulette games.