Audio Toolbox: Pro Sound

Audio Toolbox is a great collection of useful sound utilities for iPhone and iPad.

NOISE LEVEL METER
For smart sound and noise measurement;

TONE GENERATOR
For making audio waves with different frequencies;

SPECTRUM ANALYZER
For visualizing audio signals;

DICTAPHONE
Afraid to forget something? Record it!

With HQ quality of audio and understandable tutorial for each utility you will have no problem mastering this app.