app for measuring work speeds on the mines

We require an app for the mines. It must measure the work-speed of an operator operating an excavator. This operation of digging up dirt and putting it quickly in a truck is called a "dig rate", the speed at which you dig up the earth and fill a truck. The app must be able to measure Dig rates over an hour, that is "measuring average bucket payloads". In other words, the app is started when the timing of the excavator starts, and the app begins to measure the amount of buckets of material that are being filled by the excavator operating the excavation machine. The app acts like a stopwatch and must be able to show the result converted into seconds and then divided by the payload. It's a way or working out how fast an excavator operator can load a truck filled with bucket-loads of earth from a mine site. It's a very simple calculation. A pretty good example of how it works is as follows: It takes 2.09seconds = 129 seconds truck's payload is 238 tons per payload which is then divided by 129 seconds which = 1.84 x 3,600 (seconds in an hour) - which gives you an instantaneous dig rate of 6,624 per hour and that is your operator performance = 6,624 238 tons divided by 4 buckets that he put in, which = 59.5 ton per bucket = this operator's average bucket payload The calculation is seen in the video. There are video materials for you to look at - example attached. We ask that you please immediately provide a visual workflow example of how the app design would look like. Thank you.