I play piano in real life and I've been asking myself why I haven't tried any of these. There's several out in the app store, but I'm wondering which one you guys use? Which is the best? Are there any that allow you to play both left and right hand at the same time? Any cool features??
The only piano app I've tried is Pianist. At the time I bought it, it had the best reviews of all of the piano apps. Since I have been happy with it, I haven't tried any of the others. Since they updated Pianist to allow a double keyboard (one for each hand, obviously) as well as being able to customize the size and number of keys visible, it has only gotten better and better. There are a lot of piano apps, and some of them have only an octave or two. Some have terrible sound quality. Some are just plain useless. You can see reviews of Pianist (as well as people demonstrating their "pianist" skills!) on YouTube.