This is pretty cool, from a "check-in-self-serve-here" perspective.
In contrast, in Quebec Canada, the QR codes are issued to people once they get vaccinated, and contain the person's name and vaccination(s) statuses, and digital signature by the issuer directly in the QR code.
The government then published 2 apps on the app stores:
* App for users to easily host the QR code (instead of email/PDFs/etc), but more importantly:
* App for businesses to scan the user-presented QR code and validate the signature, to allow into the premises (after also checking a photo ID to ensure person face matches ID and ID name matches name in QR code)
The above is because some businesses, like sit-down restaurants (even if eating on the terrace), are required to ensure patrons are fully vaccinated.
I don't know if the "scan" app also remembers who it scans for contact-tracing purposes or not - but there's a separate contact-tracing app for that, also published by the government, that uses iOS's and Android's contact-tracing facilities.