Spectrum Analyze is Red Pine Labs’ audio-analyzing app, and perhaps the best available on the Android market. With more than 50,000 downloads and a rating of 4.3 out of 5 stars, the app can be downloaded for free in the Google Play Store. Special features are available on an upgrade for just $1 USD.
Free features include a pause, peak reset, the ability to save a screenshot with a single button, and a share button.
For the extra $1 USD, the user can set high and low limits for the X and Y axis, the number of seconds per frame, and size of FFT.
Get it here: