You could store money digitally on a card. Moneo did that until 2015 and it was used in France as a wallet for paying meals in school canteens for tertiary education. That system was phased out just as I left university.
I remember writing an app in Java to read the balance on a card with my laptop which had a built-in smartcard reader, because I was too lazy to go to a station. Everyone in the classroom then promptly asked me to check their balance... and a few asked if I could top it up somehow.
I remember writing an app in Java to read the balance on a card with my laptop which had a built-in smartcard reader, because I was too lazy to go to a station. Everyone in the classroom then promptly asked me to check their balance... and a few asked if I could top it up somehow.