The day after announcing it had purchased cross-platform mobile tool vendor Xamarin, Microsoft officials are offering a few new details about the company's Universal Windows Platforms onboarding strategy.

As previously rumored, Microsoft is dropping work on its Android "bridge," or toolkit for bringing Android apps to Windows 10. It's putting all its mobile-toolkit eggs in its iOS bridge basket instead.

Microsoft execs are not yet going so far as to declare that Xamarin will be key to Microsoft's quest to attract developers to write Universal -- and not just Universal Windows Platform -- apps, using a common framework and set of tools, that target operating systems including, but not limited to Windows 10. That's what many of us industry watchers are expecting may happen at some point.

Instead, Microsoft officials are opening up more on what's next for the company's bridges, or development toolkits, for Windows 10, which they expect to offer alongside Xamarin's technology which allows C# and F# developers to write native apps for iOS, Android, Windows and Mac OS.

"We're excited to have Xamarin join Microsoft and the opportunities it will offer developers - making it easy to share common app code across Windows, iOS, and Android apps while still delivering fully-native experiences for each of the platforms," said Corporate Vice President of Program Management for the Windows Developer Platform team Kevin Gallo in a February 25 blog post about Microsoft's evolving Windows 10 developer strategy.

But the majority of Gallo's post is a status report on Microsoft's latest shift in its Windows 10 bridge plans.

About a year ago, Microsoft execs made much of the company's plan to help lessen the mobile-app gap for Windows and Windows Phone via a handful of bridges.

Microsoft delivered the bridge for turning web sites into Windows 10 apps, which was codenamed "Westminster." In partnership with MobilizeNet, it also delivered a bridge for bringing Silverlight apps to the Universal Windows Platform.

But Microsoft delayed its "Centennial" bridge for bringing Win32 apps to the Windows Store, and was rumored to have also delayed and possibly tabled its Android brige, codenamed "Astoria."

However, it wasn't until Gallo's post today that Microsoft officially acknowledged the company is dropping plans for its Android bridge.

Gallo said that Microsoft received feedback that developers found having both the iOS and Android bridges confusing and unnecessary, presumably because many mobile apps exist on both of these platforms already. The iOS bridge will be Microsoft's only bridge for bringing ,mobile code to all Windows 10 devices, including Xbox, Gallo revealed today.

"We have carefully considered this feedback and decided that we would focus our efforts on the Windows Bridge for iOS and make it the single Bridge option for bringing mobile code to all Windows 10 devices, including Xbox and PCs. For those developers who spent time investigating the Android Bridge, we strongly encourage you to take a look at the iOS Bridge and Xamarin as great solutions," Gallo said.

In August, Microsoft open sourced the code for its "Islandwood" bridge, which is the one for developers interested in porting their iOS apps to Windows 10, to Github. Last week, Microsoft released an update which included the first ARM32 preview compiler drop for Islandwood, Gallo said.

Last Fall, Microsoft delayed availability of the "Centennial" bridge, which is the one for helping developers bring their Win32 apps to Windows 10 devices, until some time in 2016.

Gallo said today that Centennial is "in testing with a set of developers now." He said Microsoft plans to have "an early iteration of the tools soon," and will expand to support more developers after that.