There is no "the app". There are 100s of sellers, and each of them has different processes. Some sell smart cards at the ticket windows, most have apps, and som

There is no "the app". There are 100s of sellers, and each of them has different processes. Some sell smart cards at the ticket windows, most have apps, and some have both. Only the price and the basic rules of validity are nationwide. Some offer extra regional perks.