Thursday's release of the Google Wallet app represents a challenge to the Passbook program that Apple has built into the iPhone's operating system.
Both Google Wallet and Passbook allow iPhone users to store loyalty cards from some merchants and scan coupons offering discounts.
Google Wallet also allows its users to send money and make purchases on some mobile websites by storing a debit or credit card account on the app. Payment information can also be stored in Passbook.
The arrival of Google Wallet on the iPhone comes a few days after a similar version was released to smartphones running on the Android system made by Google.