Of course it works. All you're doing is COUNTING. The point is that your brain isn't big enough to remember all the previous cards played so this program would do that for you. I'm sure it's quite the simple program. Good luck in jail.
I haven't tried it, but AFAIK, it just teaches you basic strategy and how to count cards. I don't think it's intended to be used to actually input card numbers at a casino table, lol. They don't allow cell phones at tables and you can't hide an iPhone from dealers, casino security and the eyes in the sky. Card counting takes tons of concentration and doesn't work well without a group (watch 21, you'll see why). They notice if you go from small bets to a large bet suddenly. Try to pull that off more than a couple times and you're caught and escorted out. It's not illegal, but the casinos have the right to kick you out and ban you from coming back. Anyway, they use multiple decks now, so it's a lot harder than it was back when the MIT guys did it.
Winner winner chicken dinner lol. You're not going to win any money with this app, but if you work hard enough, maybe you'll get yourself on the Nevada gaming commission black book
It's funny that you brought this up. Las Vegas has already issued a statement that anyone caught with an iPhone/iPod touch in their casinos using the App will be dealt with properly because it is illegal.