A new app from MasterCard is capitalizing on the popularity of Apple Pay, the new service that lets people pay for goods and services with their smartphones.

MasterCard Nearby tells people where to find stores that will take their MasterCard via contactless payments. There are over 220,000 retailers across the United States that can accept Apple Pay and MasterCard PayPass, the contactless payment system that lets people hold their cards or phones near a register and pay without swiping a card.

Merchants that accept contactless payments include Subway, Toys R Us, Walgreens, Whole Foods Market, and the Apple Store.

How to make a contactless payment

Here’s how it works: when you hold your contactless-enabled smartphone or credit card near the contactless payment reader, your information goes to the retailer automatically. It’s encrypted for security, so there are no worries about identity theft or fraud.

If customers are using Apple Pay on their iPhone 6 or iPhone 6 Plus, they then put their finger on the Touch ID or enter their secret code to authenticate their purchase.

Apple Pay works by loading credit and debit card information onto your phone. Bank of America, Capital One, Citi, and Wells Fargo are all participating in Apple Pay, allowing their customers to load their card information to mobile devices and make payments anywhere that accepts Apple Pay and other contactless payments.

What happens with the money?

If you use a linked debit card with Apple Pay, money is transferred from your account in minutes, just as it would be if you used your debit card the regular way by swiping it. It’s the same with your credit card. A charge will appear on your account as soon as you pay using Apple Pay. The payment is the same; it’s just a different method.

The MasterCard app aims to help consumers who may be confused about exactly where they can use their new Apple Pay enabled smartphone. Changing from the traditional methods of payment can be hard—like teaching an old dog new tricks. But an app to help you locate merchants that can accept your contactless payments takes one piece of the guesswork out of this new technology.

The MasterCard Nearby app is free at the iTunes App Store. It also tells users where they can reload MasterCard prepaid cards, get cash back, and find an ATM.