For the 3DUI Contest version, please checkout the reardme file in 3DUIContest folder Even though the work was not submitted to the 3DUI 2015 Contest in the end, it's a good tutorial for android programming in Unity platform.
The Plugins/Android folder have a jar file (sensorfusion.jar) which is a java package from another Android project. In file Assets/Scripts/MobileCtrl.cs, it shows how to use the jar file very briefly