Earlier quoted context omitted.
Perhaps something like this: https://youtu.be/_BSfO9LAIqg Looks cool, has NFC and flashing LEDs and fits in your wallet. The NFC chip can be reprogrammed with an app from your phone.
Yes - Precisely!
Inspired by this: https://www.hackster.io/news/how-to-make-an-nfc-equipped-pcb...