Nice! I’ve done some pitch detection with librosa before. Curious about your FFT/HPS implementation. How did you handle the time-frequency tradeoff for the spectrogram windowing? Or is that less of an issue with the other algorithms available as fallbacks
Your iOS device mute instructions are too verbose. Not all iOS devices have a mute switch. The latest devices have a mute button. Copy can be simplified to "Make sure your mobile device is not silenced"
I can sing rather well, and this is completely off. About half the notes are wrong.
My voice does have quite a few harmonics though. Maybe that is throwing the algorithm completely off?