Use bank or bus cards on your smartphone
Mi Smart Cards is a Xiaomi app that's necessary to use features such as paying with your credit card or adding your bus card to your smartphone. To do so, your device must have NFC connectivity, as well as other apps to add the cards.
To add a bank or bus card, the physical card is required. To add it, go to the add card section in the corresponding app and put it against the back of your device, which is where the NFC is located. After that, you'll no longer need the physical card to pay for things. On some devices, simply placing the NFC card against the back of the device will automatically open the app to add it.
In addition to physical cards, you can also use NFC to add other items to your device. One example is smart locks, which let you unlock your phone in various ways: via Bluetooth, physical keys, a PIN, or your fingerprint. Some of them also allow the use of NFC cards, or if you put them in configuration mode, you can add them directly to your device's NFC.
So if you have a Xiaomi, POCO, or Redmi device, the Mi Smart Cards APK is a must in order to get the most out of your cards with NFC connectivity.