I have about 4 other paid piano apps. This one has the best piano sound quality. Few annoyances that should be fixed for 5/5 stars:
1) Save the selected settings. (sustain, #of octives on display etc.)
2) Instead of tuning and metronome, have the sustain and damper on/off display on top at all times.
3) Please consider making the # of keys to display an option instead of # of octives.
Just look at the "Pianist" app for reference. They have the best GUI/controls, laid out perfectly.
Yaju about Virtuoso Piano Pro Classic