I spent years using Windows, then switched to Mac, but now back to Windows 10 which is an enormous improvement over anything I have previously used, and loving it.
I would really like to have a Windows 10 Phone app. This OS I realise has low usage in the USA, and more widely used outside the USA (that's me), but is a great platform and is now really fluid and nice to use. It also is designed so that developers can share common code between the desktop and mobile and tablet devices.
In other words, there is NOT two versions, like one of iOS and one for MacOS. It is unified, finally !