The idea is similar to Electron, build cross platform desktop apps with JavaScript, but with a native UI.
More importantly, you don't need to install a bunch of prerequisites to use it. Download 1 file and run. No install, just copy the file wherever you want it. And the applications you build with it are the same, no giant bundle of files to distribute with your app.
It's definitely not finished. I currently only have an IDE for Windows, but you can still use it to create apps for both Windows and macOS. I have a prototype of an IDE for macOS but it's not complete. Also, the documentation is pretty sparse, sorry!
I'm still working on tweaking the UI for the created apps, the differences between macOS and Windows make it difficult for the UI to look exactly the same, but it's getting there.
Anyway, would love to hear if anyone finds it interesting and/or useful!