Hello.
I’m planning on releasing my first Google Cardboard app (and indeed first Android app for some years) today.
It’s called Asteroid Belt Travel VR and I mentioned it in the Monthly WIP screenshot thread a couple of days ago. I started it out as a demonstration of the jme-cardboard project as something with few features that I could instead spend more time polishing.
It’s a dioarama-style experience situated (as you might have guessed) in an asteroid belt around a star. The user can not do much but look around on the passing rocks and dust.
I’m much into space and science, but a true scientific space simulation can be pretty dull so I’ve taken some artistic liberties with the realism. Most of all the scale is probably not that realistic. The belt would most likely not be visible across the star, both due to size and the star light obscuring it. Also the belt is very dense compared to a real one, where you could probably travel a day without seeing a rock of the size seen here.
But you never know, considering the immense amount and variety of star systems there are out there 
The app is currently pending publication as Beta. If anyone is interested in testing it before it’s released (which I hope to do during the course of the day) send me a message. It seems beta testing is relying on “Google+ Groups”. Is there anyone for jMonkeyEngine?
It’s in the app store (and free)!