Apple Pay is changing the way we buy stuff, bridging the gap between the online world and that good old fashioned universe where we walk into drug stores, fast food restaurants, and coffee shops. But it's not the only one.

PayPal is also working to break down the barriers between online payments and off-line payments, to give us a way of paying for stuff in either place, with equal ease. Countless startups are now offering Bitcoin wallet services that work in similar ways. And let's not forget about Google, whose Google Wallet service, which arrived years ago, isn't all that different from Apple Pay.

The thing is that, following the arrival of Apple Pay, it's rather easy to forget about Google Wallet. Because Tim Cook and company can so readily put Apple Pay in the hands of the people via the iPhone—and because they have leveraged their market power to bring Apple Pay to big-name merchants such as McDonald's, Walgreens, and Macy's—they have changed the payments world more quickly and more extensively than anyone else. But Google Wallet is still there. And at least in small ways, it continues to push payments in the same direction.

On Monday, WePay—an outfit offering online services that drive payments for all sorts of other companies—announced that these services now dovetail with Google Wallet. This will allow the tech giant "to support small business owners through WePay's hosted payment offering, making it easier for them to accept payments online and on mobile devices," says Steve Klebe, who handles business development for Google's payments operation. In other words, WePay's many customers can now accept payments from Google Wallet on websites and inside mobile apps.

As with Apple Pay, people tend to think of Google Wallet as a way of using your smartphone to pay for stuff in a Peet's coffee shop or some other real-world store. But you can also use it to pay for stuff online. That's how you pay for stuff in the Google Play store, the app store offered on Android devices. You can now use it to pay for car rides through Uber's smartphone app. And, according a spokeswoman for a payment service startup called Stripe, outfits such as Wish, Summon, and Sidecar are using Google Wallet in much the same way.

In plugging to the Google Wallet system—via what's called Google Wallet Instant Buy—WePay is expanding the reach of the service in the online world. "Historically, Google Wallet meant tapping your phone at the point-of-sale in a store," says WePay co-founder Rich Aberman. "But now there will be lot of places online where you can use it too."

Though the reach of Google Wallet isn't quite as impressive as that of Apple Pay, the new partnership at least shows that Apple isn't the only one changing the way payments work. "People traditionally drew a really sharp distinction between off-line and online payments. Face-to-face, you would swipe your card, and online, you typed in your credit card details," John Collison, the co-founder of Stripe, told us this past fall. "But those lines are starting to get blurred—starting to go away."