It would be awesome if Piano Booster could also suggest fingering: Analyze the song and then label each note to L1 for left thumb, L5 for left pinky, R1 for right thumb, R5 for right pinky, etc. I think you could create an algorithm to do that so that when you have to move your hand you'd know to use your index finger for a particular note so that later on a note is under your pinky for example, to keep you from moving your hand three times instead of two time.
I find some interest in this idea too. However, several folks, in previous threads, had suggested that fingering suggestions are less important as you advance. And there is the limitation that PianoBooster's feedback is great for letting you know you hit the wrong key but has no way of knowing if you used the wrong finger.
What do you think of this approach: Someone, outside of PB, analyzes a MIDI file and creates a fingering guide. It could be an HTML snippet, or labels in the PDF score (that's autogenerated by abc2pdf). This could be saved along with the MIDI file in a wiki page on that song. Then PB displays the HTML chunk in a mini HTML panel at the bottom of the window (perhaps jumping within that HTML field to an HTML anchor tag associated with each bar of music). There was a proposed feature where PB would display HTML cards at the bottom of the screen, I think it was prototyped, but not sure if its still included.
This way, beginners can see the fingering suggestions when they are first learning the song. Also, the HTML could show lyrics, background notes... and all sorts of stuff.