Similar issue with parking around here: there are metered bays which you either phone in and give them your credit card number, or use an app to do the same. I don't often park in those kinds of bays, but one hospital is totally dependent on them so needs must. Second time I chose to use the app and it was much less painful that phoning in, of course.
However, not I have the app and I notice these bays elsewhere. I took a trip into London and the place I was visiting had a car park round the back, so I figured I should take a fistful of coins. But it turned out to use the very same app and since I was that was already set with my card a registration number I just had to run it, agree I was where the GPS said I was, and it was done.
Now, I actively look for parking places covered by that app no matter which part of the country I am visiting. Sometimes this stuff works very well, although I'd be the first to be suspicious of some random app for a local business.