We hope you've enjoyed this introduction to and journey through Cardboard virtual reality development for Android. Throughout this book, we have explored the Google Cardboard Java SDK, OpenGL ES 2.0 graphics, and Android development in general. We touched on a number of VR best practices and saw the limitations of low-level graphics development on a mobile platform. Still, if you followed along, you've succeeded in implementing a reasonable general purpose library for 3D graphics and VR development. You created a wide variety of VR applications, including an app launcher, a Solar System simulation, a 360-degree media gallery, a 3D model viewer, and music visualizers.

Naturally, we expect the Cardboard Java SDK to change, evolve, and mature from this point forward. No one really knows what the future holds, perhaps not even Google. Yet here we are, at the precipice of a bold new future. The best way to predict the future is to help invent it. Now it's your turn!