Video Tachometer is a free iPhone app developed by Dmitriy Kharutskiy in the Utilities & Tools category. This innovative program allows users to measure the rotational speed of a part by utilizing the strobe light effect created when the frame rate of a video matches the speed of the part.

To use Video Tachometer, your smartphone must support slow-motion video recording. This feature is available on all iPhones starting from the 5S model. The app provides a range of frame rates to choose from, allowing you to accurately determine rotational speeds between 30 andRPM for iPhone 6 and newer models, and between 30 and 7200 RPM for iPhone 5S.

Achieving clear and precise measurements requires good lighting and manual adjustments of exposure time, light sensitivity (ISO), and focus. You can capture videos using the iOS "Screen Recording" function and take screenshots with the measurement results displayed.

Video Tachometer also offers the option to choose a video format with the best quality, although it may have a lower maximum frame rate. This format is ideal for speeds below 1000 RPM and provides enhanced image clarity. Additionally, the app allows you to enable hints for easier observation of changes in rotation speed, making the measurement process more convenient and efficient.

With Video Tachometer, accurately measuring rotational speed is as simple as using a stroboscopic tachometer, making it a valuable tool for various applications.