Which app does Xi 'an subway use to save the most money?

China unionpay express APP. Xi Metro can enjoy preferential services through China UnionPay Express APP. When traveling, you can choose the subway code page and the subway colorful weekly or monthly card, which helps to save money. China UnionPay Express APP is a mobile payment application launched by China UnionPay, which aims to provide consumers with convenient and secure payment services. Users can bind bank cards on China UnionPay Express APP to complete payment, transfer, inquiry and other operations, without using cash or bank cards to pay directly.