One QR at a Greek periptero shows snack-and-drink prices in the tourist's own language. Locals see the Greek price list. Edit prices in 5 seconds.
Browser-locale + IP geo route tourists to a localized price card; Greek-speaking customers stay on the local list. Price edits go live across all languages from the owner's phone.
Free tier includes 1 permanent QR and the recovery key — upgrade the slot with the exact modules this case uses whenever you need them.