Appload and Xovi open up a range of options. You can build a simple frontend in QT and have a backend in a language of your choice serve as an API. Appload handles the display / xochitl for you. I've built tons of little apps like this - and bigger ones.
https://github.com/asivery/rm-appload https://github.com/asivery/xovi
Installing these used to be a bit of a hassle, but ReManager and Vellum make it a breeze: https://github.com/rmitchellscott/reManager