If you want to transform your android applications into Windows applications, you have the Windows Bridge available for Android, a project that was known as Project Astoria or Project A and that will be launched this year to allow reuse of the Android code.
With this Windows Bridge for Android it will be possible to create mobile compatible Windows applications, use a Microsoft interoperability library that allows integrating Microsoft services in our app, debug the application with our preferred IDe and publish it in the Windows store.
The android project is still being built, but we can already request to enter the developer group that is testing it.
The fact is that today they announce something similar for iOS, information available at blogs.windows.com, where they indicate that the project, called before Project Islandwood, opens its doors in its first version, with the expectation of having it ready for use within a few months. They will release it with open source, under MIT license, and describe it in detail in this article.
This alpha version is already on github. Require developers to use their knowledge of Swift and Objective C, and import the code into Visual Studio in order to develop the desired Windows application.
As you can see, efforts continue so that the number of applications available for Windows is similar to what we have on Google Play and iTunes, although it will take a long time for developers to achieve that goal.