It's great to get such a glowing review from Andy on one of the TWiT Network's most popular shows.
Longer term, I'd watch out for Tonara: they say their app can listen to what's actually being played and follow along, even if there are dozens of simultaneous notes. Scoble interviewed them recently: http://scobleizer.com/2011/09/15/tonara-an-ipad-app-for-musi...