I was doing some investigation on using RFID cards on iOS. I didn’t realize that the NFC readers I had from Feitian were all CCID readers. That means that they can talk to iOS using the smart card support added to iOS 16. However, since the cards are not PIV smart cards, I had to develop a CryptoTokenKit extension for reading the UUID from the RFID. Once I got that working, I created an Autofill Credential Provider (usually used by password managers). So now instead of entering your username and password, you can tap a RFID card! It is a proof of concept app that just takes the UID of the card and looks up the username and password, but it could definitely be made more secure (perhaps add a PIN, store the password in the Secure Enclave, etc).
Here is a video explaining a bit more and showing how it works: