Octave

Octave is a real-time spectrum analyzer for the iPhone and iPod Touch that uses time-domain analysis, rather than FFT techniques. Octave follows strict ANSI certifications for sound analysis, found on multi-thousand dollar sound equipment. You can have pro-quality sound analysis on your iOS device for tiny fraction of the cost! See your sound in detail with up to 1/12th octave bands. Quickly find out peak frequencies with a swipe to access the cursor, and tap-and-hold to freeze the audio with live spectrum averaging (it will turn blue, slow down, and look completely radical).