Spectrolite

Spectrolite visualizes the frequency content of sound in real time in the form of a spectrogram.

Spectrolite features a logarithmic frequency scale and constant-Q analysis for a perceptually and musically meaningful display that covers the full frequency range of human hearing. Intuitive touch panning and zooming lets you dive in and explore the spectrogram in detail.

The Pro feature set, available as an in-app purchase, adds grids and scales for time, frequency, and amplitude. This expands Spectrolite into an audio measurement tool that you can use to measure frequencies, musical pitches, durations, and relative amplitudes.