1. DESPLAY
The power spectrum of sound is displayed in the range of 20 - 20000Hz.
You can zoom in/out the spectrum by pinching in/out smoothly.
Also landscape orientation is supported.

2. USEFUL
While "hold" switch is ON, the maximum values are displayed in red color.
You can select "Mean" or "RMS" as the way of smoothing the spectrum out.

3. LOGGING
By sliding "log" switch, the logging mode is started.
To choose a past log from "History" tab, you can pull it from iPhone via email as a CSV file.
The CSV file can be edited with Excel etc.

4. AVAILABLE
Without cellular data service, the full functions are available.

5. BACKGROUND PROCESSING
You can use the logging function even when iPhone in your pocket.

6. TECHNICAL NOTE
Sample rate: 44.1kHz
Bit depth: 32bit float
FFT window function: Blackman
FFT samples: 8192