Classical Guitar (iTunes App Store)
it simulates the sound of a classical guitar (nylon strings). As you might guess, it is not quite the same as a physical classical guitar (or any other guitar for that matter). The app limits you to playing within a set of six chords (although eight show in the stock screenshot here). You can’t really play anything other than chords although you can choose which six chords are available. Multi-touch limitations make the preferred technique to select the chord with one hand, lift that hand away from the screen, and then use the other hand to strum. Individual strings can be “plucked.” However, the multi-touch limitations limits how fast you can pluck. String plucking on the screen is more like hammering on a physical guitar. This leads to a bit of cognitive dissonance between what you are trying to do (pluck) and what you actually do (tap on a string).
But, those nit-picky details aside, the app sounds good and is a lot of fun to play with. And, hey, it is free.