Starting today developers can now link Windows Store and Windows Phone applications to create the already-announced “universal” applications that Microsoft announced recently at its Build developer conference.

Microsoft is working to unite development for its two core Windows platforms, incentivizing developers to create apps for Windows by making it easier to target two separate audiences while reusing much of the code between the applications. Microsoft is in the process of harmonizing its stores, but that process is not yet complete.

The company will eventually bring the Xbox One, another Windows-based machine, into the universal app game. The gist of a universal Windows app, according to Microsoft, is that it allows consumers to snag an app once, and download it for all compatible Windows devices. As we know, the devices that will be compatible with the app varietal will grow.

This morning, Microsoft released Windows Phone 8.1 to developers. TechCrunch published hands-on notes of the new code, the feature set of which was detailed at Build.

Also out today for developers is the ability to reserve application names for Windows Phone applications. Previously, this was only available for Windows Store apps. Keep in mind the theme: Harmonization.

Over the weekend, Microsoft announced the consolidation of application pricing tiers to better match Windows Store and Windows Phone applications. This change will see the addition of $0.99 and $1.29 apps into the Windows Store.

Shifting gears entirely, Microsoft’s Joe Belfiore announced today that the company’s OEM toolset to help manufacturers get up and running building Windows Phone handsets is live as well. You can’t do this in your garage, but the help could assist smaller, regional OEMs jump aboard Windows Phone. I suspect this offering is more enticing now that Windows Phone devices with smaller than 9″ screens are free.