I had a similar idea and started with an android app [1] for creating an app template with a simple interface directly on the device. It's not as powerful as this, but maybe I can implement basic support for these templates. But right now this would be only like a viewer and not something that can be used for own apps, not sure how useful that could be.
I thought about something like this for autonomous cars. The game engine could simulate all the sensors in a car. Then it would be possible to use this as training data. Would be fun to create a racing game out of it to let different algorithm compete against each other.
Does this already exist? Google should have something like this, but probably not freely available.
I did something similar for Go and Java. It's simpler if you don't need the whole API, but of course not as powerful.
https://github.com/bashtian/jsonutils