ParkPlus in Calgary works well.  Winnipeg also allows one to pay by app (PayByPhone).  To be clear, though, most/all of these allow you to use coins or your credit card.  The apps also require you to add money to your account. For how often I need to pay, I can't be bothered having money on my app account, though they do have the advantage of being able to add time and not having to go feed the meter if you are taking longer than you paid for.