I remember this from a few years ago when it was posted to HN.
I remember it for originally shipping with a really good clone of the macOS windowing system down to the three colored buttons - when you clicked them the buttons popped out to make clicking the right one easy and it was really well done, had a native feel to it and was super fluid.
It allowed me to dream of running macOS on my iPad...
It was later removed, but I felt the need to mention that.
