The more I use Google Cardboard, the more I'm impressed by it. You wouldn't think such a cheap assortment of parts (well, and a not-so-cheap smartphone) could produce such an immersive virtual-reality experience, but the proof is in the putting on.
As I explained in Getting started with Google Cardboard, you can either build a kit yourself or buy one pre-assembled. But what I didn't realize is that you can use it with apps designed for other VR headsets (such as the Durovis Dive). In other words, you're not limited to Google's proof-of-concept Cardboard app or that handful of Chrome Experiments.
In fact, you might be surprised by some of the cool apps that work with Cardboard. Below I've rounded up five you absolutely must try -- preferably with some sort of game controller so you can move around. Options include the Snakebyte iDroid:con or a PS3 controller connected via USB. I used an Impulse Bluetooth controller and it worked quite well.
Halls of Fear VR Demo: A simple but totally effective game in which you navigate dark, spooky tunnels in search of cubes.
Shadowgun VR: This sample level from the amazing Shadowgun first-person shooter pretty much blows away everything else. After a non-interactive fly-through, you're plunked into the level where you can look around at the amazing level of detail. And if you have a game controller, you can move about as well.
SpaceTerrorVR: Similar to Halls of Fear, but with a space-station setting, even cooler graphics, and at least a few genuinely scary moments. Don't let the monsters touch you!
Tuscany Dive: Ever wanted to visit a seaside villa? Tuscany Dive takes you there for a lovely afternoon stroll. Really it's just a fancy demo, but still a great showcase for VR. If you look straight down, you can toggle on or off the auto-walk mode, which lets you move around without a controller.
VR Cinema for Cardboard: Released just two days ago, this simple app lets you view MP4 videos (stored on your phone or Dropbox) in all their full-field-of-vision, simulated-3D glory.
Another app that's definitely worth a look is Flight VR Demo, though I had a hard time getting it to work (meaning I could never figure out how to take off).
Have you found any other must-have apps for Google Cardboard? Name them in the comments!