[noobermin]

Let's imagine the system engineers are smarter than that: if you have a smart phone, you can use the app. If you don't, there'd be a terminal in the station you could use. I'd imagine the engineers for this could have thought of that.

[retbull]

Easy enough to just assume people have smart phones and only have it in cities where mostly people will have them even the poorer people. A cheap smart phone isn't that expensive any more.

[listic]

It's not just the cost, really: I know I can have a second hand smartphone for peanuts. There'll probably always be some people who don't use smartphones, for whatevre reason.