There's also https://www.lume-pad.com/ which I'd love to try out but can't drop a grand on.

I have access to a looking glass (the smallest one) and it's quite fun - especially when paired with a Leap Motion for hand tracking. I had the pleasure of demoing it to William Latham who adapted his work for it. ( http://latham-mutator.com/ )

I ported one of my proc gen demos to it and it's in their store - but I don't think you can link to it. The repo is here: https://github.com/IxxyXR/Polyhydra-upm ( and https://github.com/IxxyXR/Polyhydra )