A TimegrapherAdjust your mechanical clock by your self.Just run this app on your phone and put your phone near your cuckoo clock or grandfather clock.This tuner samples and analyze clock sound to displays the frequency of pendulum in real time. You can easily measure clock frequency to adjust pendulum.My Galaxy Nexus detects the pulse of Rolex Datejust in calm environment.Not for digital clocks.Not working in noisy environment.Set microphone direction toward a clock.** Basic version display wave graph and pulse interval histogram.** Frequency display requires 'Premium' upgrade.** Do not upgrade if the 'Basic' version fail to display pulse interval histogram.- Review from Mr. Kojimahttp://www.thewatchsite.com/index.php/topic,42142.0.html - Preset exampleRolex or mechanical watch: Target frequency: 4 or 5Hz, Sample duration: 2Sec, Sensitivity: manual 50Most pendulum clock: Target frequency: 1 or 2 Hz, Sample duration: 5 or 10 Sec, Sensitivity: mediumFAQ.1) in the settings there is a sensitivity option with a high, medium, low and 3 manual settings, can you explain how this changes the resultsIt determines sound amplitude threshold for detecting clock sound. If your clock sound is loud you may reduce sensitivity. This will allow more environmental noises.If you increase the sensitive, you may measure hand watches. But small noise may measurement errors.2) why does the detected frequency change between light grey, black and redRed means smaller drift during the measurement interval while grey means that measurement may have an error.3) the average frequency does not always calculate, it stays at NaNThe 'detected frequency' should be red continuously. 4) how do you calculate the pulse drift % abs(max detected frequency - min detected frequency)/ detected frequency during 1 detection cycle.5) what are the 2 graphs showing and what data are you using for the calculationsThe size of bars in the upper graph should be almost the same.The bottom shows amplitude of sound wave recorded from micro phone.6) are newer versions of the app being developedI'm planning of better sound filtering logic. Not done yet.