Pittsburgh finally has a parking app. Once you register your license plate and credit card number, you won't need quarters or use a credit card to park at a meter in the city again.
You will need to note the "zone number" posted on the parking kiosk closest to your car. You punch that number into your phone, choose how much time you want, and then your countdown timer begins.
There is a fee of 8 cents each time you begin a parking session with the app as a service fee to Parkmobile.