Vibration Meter is in the 4th set of Smart Tools collection (seismograph, seismometer, body tremor).This app uses the phone sensors to measure vibration or the earthquake, and it shows a reference as a seism detector.The measured values are the Modified Mercalli Intensity scale(MMI), and just for reference. If it is inaccurate, you can calibrate it so that the maximum value is about 10-11.* Pro version added Features:- Sound Meter Pro is included- Alarm and beep added- More models are calibrated- No ads.* Do you want more tools?Get [Sound Meter Pro] and [Smart Tools] package.For more information, see the manual, Youtube video and the blog. Thank you.