I had a similar use case as you for making apps to run on a Rasberry Pi for my staff to use in my business (Chocolab.com.au) I discovered appjar.info which has

I had a similar use case as you for making apps to run on a Rasberry Pi for my staff to use in my business (Chocolab.com.au) I discovered appjar.info which has been so simple to use for quick ugly interfaces. It is built on top of tkinter