U-RETORI app for iPhone and iPad

U-RETORI is an accelerometer utilizing the acceleration sensor of iOS devices. It records acceleration wave form of X, Y, and Z components of the device and calculates power spectrum by FFT (Fast Fourier Transform). From the power spectrum, dominant frequencies of various vibration wave forms can be obtained easily. Data is saved as csv file and transmitted to your computer via iTunes.
[Examples of use]
What are the frequencies when you walk or run?
What are the frequencies of vibrations of cars or trains?
What are the frequencies of structures such as buildings or bridges? (Some evaluates the soundness of structures from the frequencies.)