A full version app for Android, by RadonSoft.
With the help of the RTA Pro Analyzer Android app, you may now transform your smartphone or tablet into an expert audio analyzer!
This app supports calibration and provides 1, 1/2, 1/3, 1/4, 1/6, and 1/12 octave filter. Moreover, it also shows the RMS value and overall Peak value for acoustical measurements.
With this Pro edition, you can find tones and noises, then measure your audio system's frequency response. Plus, it offers more color options and scalable peak holding than the general version.
Feel free to store calibration data over time – you can always come back to your stored data in the future.