I haven't seen that particular piece of software, but I have however been using this
http://www.pocketgear.com/software_detail.asp?id=18649
I have to say that it is very good indeed. Certainly worth checking out if you like Sudokus. I emailed them with a (very) minor bug on an earlier release and they offered me a new build within 3 hours. Fantastic customer care I thought. they have since improved the game further and what's more, it's cheaper than the one you're suggesting.