Best way to make a multiplatform application

Hello Everybody,
I would like to make a multiplatform application (Windows and android) able to receive and send UPD packet.
Actually I’ve made the windows application with form but I would like to transfer it to android.
I don’t care to rebuild all the GUI it is a simple form with few buttons and textbox.
Is there some tutorial to make windows GUI able to run on android ?

Thanks for your help.

No. Because you can’t really make windows GUI run on android.

If you target multiple platforms, you use cross-platform GUI framework. Like Qt, wxWidgets, etc. Qt should be able to target android.

You can also use Unity and its GUI framework for the same purpose. However, unity is a game engine, so trying to implement a complex ui like a spreadsheet in it will be a bit awkward.