I had considered this, as I was writing an ‘app configurator’, where Corona read JSON Config files that built the app screens on the fly. To do so, the customer would need to create the JSON files which they would have done in a screen similar to what you posted.
The theory being they design it there, click a button and JSON gets pushed to the server and the App(s) read it.
Now all that said, I found Corona tricky for doing the GUI as it was. I know Roaming Gamer had some nice GUI stuff going on with EAT, but after some research I concluded that it just wouldn’t look right.
While it’s easy enough to put a ‘ipad’ image on the screen, and place items in it, I was concerned about how these translate to a real item as the X/Y and resolutions aren’t the same. I leant towards allowing ‘Left/Right/Center’, but that got cumbersome too.
In the end, I decided that laying out the screen in detail wasn’t going to cut it, and I’ve sat on it.
(A shame really as the app was actually working on pulling JSON on the fly and ‘building’ the app experience real time.)
Maybe I’ll get back to it…
So, while I wrote a bunch of stuff that didn’t solve your problem, I hope that some of it fits what you’re doing, and gives you something to ponder as you move ahead.
Cheers