Yup, that's the app I use. For a while I used an NFC tag instead of a QR code, but the tag started failing and I didn't want to solve 10 math problems every time it did.
Yup, that's the app I use. For a while I used an NFC tag instead of a QR code, but the tag started failing and I didn't want to solve 10 math problems every time it did.