Somewhat related questions: How can I use an Android phone as a room keycard? Is there an app for reading a card and acting as a tag? How can I use an iPhone

Somewhat related questions: How can I use an Android phone as a room keycard? Is there an app for reading a card and acting as a tag? How can I use an iPhone as a room keycard? Why can't I easily add it to Wallet? Is there another app for that?