This app is a timegrapher for tuning fork watches which were introduced by Bullova in the 1960s under the Accutron label. The app uses a microphone to measure the accuracy of tuning fork watches. Please see the trailers for help on obtaining accurate results. The accuracy of the app is dependent on the clock accuracy of your audio card. This manifests itself by a constant error between 0.3 and 1 sec/day. Tuning fork watches are typically adjusted to run 2 sec/day slow on a timegrapher. This will lead to almost 0 sec/day deviations when the watch is worn.