Who needs Windows? Soon, you'll be able to use Chrome-based standalone apps to communicate with a Fitbit, sort through an iTunes music library, and pay for in-app purchases via Google Wallet. Google recently announced a slew of updates and additions to the APIs (application programming interfaces) available to developers making packaged apps for Google’s browser.

You may not have heard of packaged apps, as they're currently still in the development stages. Packaged apps are built on top of Chrome using Web technologies such as HTML, CSS, and JavaScript. The big difference between packaged apps and regular Chrome apps is that packaged apps are standalone programs that operate in a separate window and can—crucially—run offline. They are also stripped of all the typical browser “chrome” such as the URL address bar and tabs, to more closely resemble a typical PC application.

The developer preview of Chrome's packaged app launcher running in Windows.

Packaged apps will give Google the ability to invade the traditional desktop with its own selection of Chrome-based apps that aren’t dependent specifically on Linux, OS X, or Windows.

Taking the online offline with new features

Google has been steadily working on improving the functionality of packaged apps as it gets the feature ready for a primetime release. Some of big new features tipped by Google on Monday include the ability for packaged apps to communicate with Bluetooth devices using the 4.0 spec. Chrome’s new Bluetooth support includes the ability to talk to low energy devices like fitness bands and heart rate sensors.

Packaged apps can now also offer in-app payments using Google Wallet. First tipped off in May when it appeared in the Canary early build of Chrome, in-app payments will make it easier to sell virtual goods in games or allow users to quickly upgrade to an app’s paid services.

A new change to the media gallery API adds your PC’s iTunes music library as a default source for importing and playing music in a packaged app. It’s a little surprising the media gallery API didn’t include the iTunes folder as a default choice from the get-go considering that most media apps automatically scour the iTunes library for music. Since the media gallery API needs to read content from personal files on a PC, the apps using this feature will be required to ask for user permission before proceeding.

Beyond support for Bluetooth, the iTunes music library, and in-app payments, there are also a few important but not-so-exciting additions. OAuth 2.0 support will let you sign-in to packaged apps using your Google account or third-party accounts that support OAuth 2.0, such as Github and Foursquare. The analytics API will let developers collect bulk, anonymous information about how people use their apps, and the native messaging API will let packaged apps access device hardware such as sensors.

Unfortunately, packaged apps aren't quite ready for the masses yet. For now, they're only available to users on Chrome’s developer channel, though their appearance in the dev channel signals that a public release is likely coming sometime in the near future.