You can now use Android Pay to pay for your Lyft ride.

You can also use it to pay for your grocery delivery from the Instacart Android app or clothes from JackThreads. That's because the mobile wallet has added support for in-app purchases. We've explained all you need to know below.

Android Pay is a new mobile wallet service from Google.

It launched in the US last autumn and can store your credit cards, debit cards, loyalty cards, etc. It's basically the new Google Wallet (only it's supposed to be "better, more convenient, and secure"). Android Pay works with all NFC-enabled Android devices running KitKat 4.4+. It also supports any mobile carrier and any tap-and-pay location across the US.

When Google first unveiled Android Pay in September, it said you would be able to pay for goods at store by simply unlocking your Android phone like you normally do (which also enables Android Pay to authenticate your transaction), then placing it near a merchant’s contactless terminal, and that's it.

Remember, Android Pay works wherever NFC payments are accepted, which is practically at every merchant. You can read more about Android Pay, including how it works and which US banks are supported, from here.

At launch, Android Pay did not allow you to make purchases within apps.

Google said in September that it was working with various developers to add a "Buy with Android Pay" to their apps, so you could tap that button to swiftly checkout instead of entering your credit card and shipping address each time you make a purchase. Now, roughly three months later, it is finally ready to go live with that feature.

Starting 15 December, you’ll be able to use Android Pay to checkout within many Android apps in the US.

All you have to do is tap the Android Pay button in the Android app, then confirm your information, and you’re done.

You'll of course first need to make sure you've added a payment card such as a credit or debit card to Android Pay before you can get started. Go here to learn more about setting up Android Pay and adding cards.

Google said Android Pay never shares your card details with merchants.

Currently, only the following apps support in-app purchases in Android Pay: Doordash, Fancy, Handy, Hotel Tonight, Houzz, Instacart, JackThreads,, Lyft, Opentable, Parkwhix, Printicular, Spothero, Spring, Vinted, and Wish.

Google said more apps should support the feature in the coming months. Developers can go to the Android Pay API developer site to learn more about how to add Android Pay and this new feature to their apps.

It's not clear when Google will launch its mobile wallet in the UK. The company said Australians can expect it to arrive in their country sometime during the first half of 2016, and that it is working with many of Australia’s major financial institutions (including ANZ and Westpac) as well as MasterCard and Visa.

Australia is just the start; Google will add "more countries throughout 2016".

For a limited time, Google is offering special savings to people using Android Pay in select apps. You can get $20 off on OpenTable dining, for instance, as well as $10 off your Lyft ride, $10 off DoorDash, 30 per cent off Vinted, etc.

Check out Google's announcement post for more details.