17!!! Google Pay lets you store some loyalty cards in there - see https://support.google.com/pay/answer/7644069?hl=en
The NHS App (my employer!) lets you register your organ donation preferences. TBH, I think the card is just a hangover from when records weren't digitised. From Spring, the law has changed to presumed consent - https://www.organdonation.nhs.uk/uk-laws/