I think there's definitely a gap in the market for something a bit simpler: there have been a good number of times when I've been stumped by a word or two in a sentence (in Polish) written on something in the street, and have resorted to taking a cameraphone photo and translating later when at home.
Sadly, as I'd love to have a play, the app store says that it's incompatible with my cheapo ZTE blade.