Helpful tool for this beginner

Im studying Pianoforall and need some help learning to read the bass clef. This little app is very useful.

I gave it only 3 stars because I hate smiley faces and dont like having to look for the little red X or the smiley to find out if Ive got it right or wrong. A buzz for wrong or bell for right (for instance) would be more logical since were dealing with sound in the first place, and having to take your eyes off the notes is a distraction and slows you down.

textplus about Piano Tutor App, v4.3