What is the source code format for the GUI wrapper for Android, iOS, and Windows Mobile applications in XML?

Question

Android

What is the source of the application interface for Android, iOS and Windows Mobile?

Answer 1

On Android, markup is stored in XML format + java binding with code.
At Windows Mobile in XML (if we take a modern stack), there is XAML + C #. XAML is also XML-like markup.
For IOS, if we take Swift, the scenes (storyboard) are in a file with XML-like markup (.storyboard files)

Answer 2

What do you mean?