You can actually use Gooey for any arbitrary program or language (if you don't mind configuring a few of your cli arguments in python). Gooey technically just uses Json behind the scenes, but Python remains the most first class way to generate that blob of json.

I wrote a brief guide awhile ago here[0]. For instance, all the screen shots and screen recordings throughout the README are done with a custom wrapper I made with Gooey which just acts as a pretty 'front end' for FFMPEG[0]

[0] https://chriskiehl.com/article/gooey-as-a-universal-frontend [1] https://github.com/chriskiehl/GooeyVideo