Most European banking apps work on GrapheneOS. Many support tap-to-pay on GrapheneOS which is unique to Europe. Curve Pay is a financial service supporting tap-to-pay on GrapheneOS in the European Economic Area and UK. PayPal has tap-to-pay and permits using it with GrapheneOS but it's only available in parts of Europe. It's the rest of the world where tap-to-pay on GrapheneOS is an unsolved problem but that can and will improve.