You can now use your smart phone to pay for parking in more parts of Philadelphia.

Since November, the Philadelphia Parking Authority has been running a pilot program with an app called meterUP that let drivers bypass kiosks in a section of Center City and a handful of other locations.

Now, the PPA says, pay-by-phone parking is expanding. The agency wrote on its website this month that the app would be rolling out citywide over the coming weeks.

If there's a meterUP sign on a block, you can use the app to pay for parking there. If there's not a sign, pay-by-phone parking isn't yet available on the street.

The app lets drivers pay from their phones and sends alerts when a motorist's time is about to expire. Users can then add more time, but the rate increases once someone parks longer than the posted time limit.

For a detailed look at how the app works, check out reporter Jason Laughlin's test drive.