Sing & See is software that analyses the voice - while you are singing - and displays information about your singing on the screen. The first critical aspect of singing is pitch, and the pitch display screen presents the pitch of the voice in a clear and musically relevant format. Of course, singing is nothing without resonance (timbre, color, ring, or any number of other descriptors for the "quality" of the voice tone) and this reveals itself in the spectrogram.
Sing&See is software that shows what your voice is doing while you sing. The software listens to your singing, analyses the sound, and instantly displays what pitch you are singing, and other features of your voice.