Hi Catalina,
"Mobile contactless" is built into the STACK Android app (the same technology being used by the likes of Apple Pay, Android Pay and Samsung Pay). This allows the app to emulate a tap-and-pay payment card using NFC on the mobile phone to transmit payment information to a payment terminal that accepts contactless.
We will also issue a plastic card in the event that the merchant does not accept contactless or say, when your phone is out of battery.
Hope that helps.
Nick
How does the tap and pay work? Will you have a plastic card as well?