As you see in the picture half bottom, If I want to create GAME UI appear like so ( with game screen in the top ),
where do I find API to create list, buttons, stacks, windows and so on…?
We don’t have pre made UI widgets so you will need to roll your own. You can use GUI templates to create reusable stuff. Check out http://www.defold.com/manuals/gui-templates/ and also the GUI API on http://www.defold.com/ref/gui/