Android Pay, which was initially announced in May, lets people with mobile phones running on Google’s (GOOG) Android mobile operating system upload credit and debit card information to a “mobile wallet.” Starting in September, shoppers have been able to use their phone to pay at more than one million retail stores in the U.S. that have point-of-sale registers equipped with near field communication technology, or NFC.

With Tuesday’s announcement, Android Pay is coming to apps, allowing people to complete transactions within an app using the credit information stored in Google’s service. Users will tap an Android Pay button in the app, confirm their billing and credit card information, and the payment will be processed. Apps that have integrated Android Pay include grocery delivery service Instacart, food delivery startup DoorDash, ride sharing company Lyft, and restaurant reservations service OpenTable, among others.

Google will be offering incentives for people to use Android Pay, including $10 off a user’s first Lyft ride, and $10 off a DoorDash delivery.

MORE: Samsung Pay Now Works with Chase Bank

Android Pay will also soon be arriving in its first international market, with service debuting in Australia in the first half of 2016. Google said Australian merchants such as 7-Eleven, McDonald’s, and Telstra will all begin accepting Android Pay payments in stores in the next six months.

Rival Apple Pay (AAPL) is already available in the U.S., U.K., Canada, and Australia. Apple is also reportedly set to launch the service in China in 2016. But Android Pay differs from Apple Pay in that it is available on many existing Android devices at launch, including older phones. Currently, seven out of ten Android phones in the U.S. are equipped for Android Pay.

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