Google Cardboard is a low cost virtual reality headset made out of cardboard, obviously, two lenses, a small magnet and some velcro. Instructions on how to make one yourself are available online.
I was quite skeptical when it came out last year. I'm not a big fan of Virtual Reality and especially when I thought of using a "low-res" screen such as a Nexus 5, combined with the onboard sensors that are not calibrated for this purpose, I didn't think it would be any good.
And back then... the official app had some bugs. While I could view panoramas made with my phone, I couldn't get the Youtube app working, it would freeze sometimes, and it just plain wasn't that impressive.
But almost a year has passed since then and several apps, made by 3rd parties, have been released for Android, that are quite amazing.
This is a very simple app, that does one thing, but it does it well. It simulates a roller coaster ride, where you can look around in 3D. Even though you can see the pixels, even though the sensation of 3D is not perfect, when you start "going down" on the roller coaster, you almost take a step back. When the roller coaster goes through some water, you brace yourself for the shock. This was the app that made me change my mind and start looking for other similar things.
This is a game where you control a little bee flying down a tunnel and you have to avoid obstacles and pick up flowers. The game concept is very old, but the new idea here is that you are going where you are looking (or more precisely, in the direction where your head is turned). Simple, but entertaining and it takes some time to get used to this new way to control the movement.
This is where things start to get interesting. With Seene you can take 3D photos of objects by pointing the camera at something and then moving the camera around a bit. They do fancy math and computer vision stuff and from the differences between the frame they calculate a depth image and reconstruct partially a 3D scene.
If you have a Cardboard, you can then view these 3D images and move them by moving your head. For objects that are close, the effect works very nicely and is impressive. If the objects are further, the math gets more imprecise and you get lots of artifacts.
This is an artistic 360 degree movie viewer. They have 7 short films available, from a very nice nature exploration, where you are in the middle of a lake, to the creation of the Walking New York art project, to SNL recordings. It is basically the dream of people who want to sit on their butt in their chair in their home and pretend they are somewhere else. :D
This is another game. Here you are miniaturized and sent into the brain of a depressive human, to find and cure "broken" neurons. The graphics are good and the controls are smooth. The game is very short (so far), but I think there is a followup in development. It reminds me a bit of Asimov's Fantastic Voyage II: Destination Brain :D.
This app is for exploring the Solar System and taking a 3D tour. It is quite impressive and gives you a bit of an understanding just how big the whole thing is. I was surprised just how much larger Jupiter is then Earth. Pretty impressive, although watching the whole 15 minutes might cause a bit of nausea in some people.
These are the 6 cardboard apps that I have reviewed and with which I was quite impressed. Not everything is perfect, some of them sometimes freeze, sometimes things stutter, my phone warms up a lot, but for a one year old product, it strongly exceeds expectations. I for one welcome our new Virtual Reality overlords. But I will still go to London in person :)))
Disclaimer: Yes, I work for Google, no, I'm not doing anything remotely related to Cardboard, all the above is just my personal opinion.