Endless runners are ideal for Cardboard because their gameplay and user input systems can easily be adapted to work harmoniously with the Cardboard viewer’s limitations. This tutorial will walk you through the steps of creating a space-themed endless runner (similar to Temple Run and many others) that can be built for use with a Google Cardboard viewer.
Along with basic mechanics and some handy tricks for creating this type of game, we’ll cover restarting the experience without removing your mobile device from the viewer and giving visual feedback to the player if they aren’t facing the right direction. At the end of this series, expect to have a fully functioning mobile app that is more polished than a test/debug build and to have learned a collection of skills that can be used to create other VR projects.
Unity's official website has a lot of documentation for building for Android devices that are very helpful.