[This is a crappy work-in-progress prototype, shared with my Patreon supporters!
Click anywhere, then allow your browser to use your microphone.
The top slider controls the target pitch/resonances, from "feminine" to "masculine". The buttons beneath that are for recording your microphone, playing back & downloading recordings. The bottom slider controls how zoomed in on the spectrogram you are.
Of course, the full app will explain pitch/resonance, give actual exercises, and – most importantly – visual and audio-based feedback, so you can get feedback on your voice, in real-time, even without looking at the app, during day-to-day conversations! But that's late. This is the crappy prototype.