Microsoft today announced the release of a new preview build of Windows 10 for people enrolled in the fast ring of the Windows Insider Program, ahead of the official release of Windows 10 on July 29. The big deal here in build 10166 is the inclusion of the Microsoft Wi-Fi app.

Details of Microsoft Wi-Fi were first leaked last month. Now it’s real, and for those in the Seattle area — Redmond, Washington-based Microsoft’s backyard — it’s available to try out now.

Gabe Aul, head of the data and fundamentals team within Microsoft’s operating systems group, explains the new feature in a blog post today about the new build, which follows build 10162 from last week:

With Windows 10, we are giving people the ability to purchase paid Wi-Fi through the Windows Store via the Microsoft Wi-Fi app. You will know when you can purchase Wi-Fi when you see “Buy Wi-Fi from Windows Store” in your list of networks when clicking on the network icon on the lower right in the Taskbar. The Microsoft Wi-Fi app provides the choice to pay with a Credit or Debit Card, a Microsoft Gift Card, PayPal, or Wireless Carrier Billing, and it helps keep your information secure since it uses the Windows Store payment system. Completing the purchase is simple as there is no need to enter additional personal or payment information if you’ve already registered in Windows Store. Right now, we’re testing this experience out in Seattle but it’ll soon open up to the rest of the U.S.

There’s also an updated software development kit (SDK) for the new build, Aul wrote. The new SDK includes updates to the Windows.ApplicationModel.Email namespace, program manager Clint Rutkas wrote in a blog post.

If you’re not already enrolled in the Windows Insider Program, you can sign up for it here and then check out the new preview build.