Adds a whole new meaning to "spending a penny" !.
I agree charging has to be seen as something you leave the car to do while you get on with something else. It is a change in mentality from just going out to fill up to spending longer but killing more than one bird with the stone/time.
I certainly would want finding a place to charge to be easy and for it to be easy to start the charge process - I would not want to be worried about apps and other hoops.
As for cost. I am deeply averse to spending more than I have to. I really wish I would be able to charge from home. It is interesting how I could give and take from the grid. Paying 70-90p for something I could pay 20-50p for would really grate. Even 50p is 250% of 20p !.
As has been stated before, all chargers will let you pay by contactless.
Apps can give discounts, although I'd assume that autocharge will look up your car when you plug in and see you've got a subscription - then bill you a reduced amount. There are some very good deals out there now, for those who public charge a lot (and, yes, that might reduce the ability to charge anywhere but if you're saving 40p or more per kWh then you may seek out a specific charging location, just as you might prefer to go to Tesco for fuel to get Clubcard points).
There are some Tesla locations charging below 30p per kWh, which is more or less the standard variable rate unit cost for electricity for a home user. You may need to charge after 10pm though, or early in the morning, when demand is low. Obviously you have to consider your time as a cost. Is it worth going to charge at night to save some money?
As someone who has often filled up my car in the small hours on the way home from somewhere, I think I would do that wherever possible. Meanwhile, some people aren't so worried about price because if 95% of their charging is at home at 6.5 or 7p per kWh, paying a premium for 4 or 5 public chargers every year is so little that - sod it - why not pay for convenience?