A nascent tool which looks to further explore this space is being developed by the guy who made Nodezator https://news.ycombinator.com/item?id=42274399 Kennedy Richard: https://news.ycombinator.com/user?id=KennedyRichard

https://github.com/IndieSmiths/myappmaker-sdd

The current version just allows drawing to make labels and checkboxes --- nothing more (but if one wanted to mock up a design which just needed those elements, it's a start)