Turn time wheel? How do you know in advance how long you stay? Where I live, you start and when you leave, you click stop. You also get reminders in case you forgot to stop.
Mostly these days all paid parking has registration camera's, and it just starts and stops parking for you automatically. However, there are like 3 or so apps that compete here so you need a profile with all of them for this to work and you also need to enable this on all the apps.
Well you can extend the parking time while not at your car. That is a big plus.
Without the app you have to find the meter, pay, print the receipt and get back to your car to put in in the window. Remember the time and get back.
With the app you can just start walking towards your destination while you start the metering.