Using the same principle of a strobe lamp, the app manipulates the camera shutter to visually detect the rpm of a rotating body by manually modifying the CPM value in the slider until the image looks stationary on the screen. The applications are infinite including but not limited to: belt inspections, gear inspection, fan inspections, detecting a rotor RPM value, viewing object and/or rotor dynamic deflections, etc. (Shutter resolution is 1Hz). The app will only run in iPhones with high frame rate and high exposure rates camera.