Vibrations is a true vibration spectrum analyzer using the built in accelerometers inside your android device.
Vibrations visualizes current accelerometer sensor data, performs a Fast Fourier Transformation (FFT) and displays the results in an histogram. The dominant frequency (peak of the histogram) is highlighted. In the settings the accuracy of the fft can be adjusted in a range from 0.0625 Hz - 1.0 Hz. Results are shown in a separate tab for each axis.

Warning: High accuracy of the fft causes heavy load on the cpu. It may disturb the results!