That can be a nuisance if you don't have a roaming subscription on your mobile I agree and you do need a smartphone. But you only need to find somewhere where

That can be a nuisance if you don't have a roaming subscription on your mobile I agree and you do need a smartphone. But you only need to find somewhere where there is wifi to do the download and then register a credit or debit card with the app. Most stations, buses, and trains have wifi.