At its I/O 2013 conference, Google announced two important features regarding Google Wallet: The first is integration with Gmail so you can pay by sending an email. The second is the launch of the Instant Buy Android API, which lets developers integrate payment features into apps for selling physical goods and services.

The first feature, which is rolling out “over the coming months” to all US Gmail users over 18 years old, lets you send money to whoever you want directly from Gmail. It’s noteworthy that recipients don’t need to have a Gmail address: any email will do. Google lets you send money for free as long as your bank account is linked to Google Wallet, or if there’s funds available in your Google Wallet Balance. There are “low fees,” however if you are sending money using your linked credit or debit card.

Here’s how it works:

As you can see, to send money in Gmail, all you have to do is hover over the attachment paperclip, click the $ icon to attach money to your message, enter the amount you wish to send, and hit send. While this is only available on desktop for now, you can still send money from Google Wallet’s website from your phone or laptop (after you set up Google Wallet to send and receive money).

The second feature is for merchants and developers who already have a payment processor but want to “simplify the checkout experience for their customers.” While Google already has Google Wallet API that works for mobile sites as well as Google Play In-app Billing for in-app purchases, now Google is inviting US developers to sign up for its Instant Buy Android API, which brings its payment service to native Android apps as well.

Here are the features Google is underlining:

  • Fast checkout for Android users buying physical goods. Users who buy on Google properties have set up Google Wallet. They can now checkout in Android apps in as few as two clicks without having to manually enter their billing or shipping information. Google Wallet securely sends this information to the developer with the user’s permission.
  • Easy app registration. More logged in users. By implementing Google+ Sign-in along with Instant Buy, developers can enable users to sign-in directly with their Google account, instantly creating an app registration. Having more logged in users allows developers to deliver a highly engaging, personalized experience.
  • More secure payments. All transactions are monitored for fraud 24/7 and covered by Google Wallet Purchase Protection to enable a safer shopping experience for your customers.
  • Easy integration. No Google fees. Since Google is not processing payments or managing fulfillment, there are no additional fees or complex integrations.

You may prefer the video version:

Apps integrated with Google Wallet will require the latest version of Google Play Services, which Google says is rolling out to all Android devices “in the next day or so.” We’re surprised Google didn’t showcase these features at I/O, but then again, the conference has just kicked off.

For more Google news, you can see all of TNW’s I/O coverage here.