This app includes an aspect ratio calculator and a timecode calculator.
It has been designed to look and feel like a real world device with jog/shuttle VTR controller and security panel type number input interface.
The aspect calculator was designed to help with calculating different possible video screen sizes for live events, but it can be used for any aspect ratio calculation you require.
The Timecode calculator is designed to take an input time and an output time and give you a duration for the time in between the 2.