*About 1.5% of people have congenital amusia *— their brain genuinely can't tell pitches apart, no matter how much they practice. Most "can't sing" cases are just undertrained ears; this isn't that.
There was an IEEE research prototype built to give people real-time pitch feedback, but it lived as a Streamlit demo — stuck on a laptop, unusable by anyone it was actually meant for.
I rebuilt it as an Android app. Mic input, a pitch detector I wrote from scratch in Dart (YIN algorithm, no native library), a live spectrogram so you can watch your pitch drift as you sing, and a slider that nudges what you're singing toward the nearest note in a key you pick.
Doesn't have to be about amusia specifically — works fine for ear training, tuning practice, or if you just want to see what real-time pitch detection looks like. Everything runs on-device, nothing gets uploaded anywhere.
