inexlib_android contains two little Android apps doing some GL-ES by using the "native way" (quite no java here).
exlib_gl draws a bunch of triangles and lines and exlib_sg draws a cube by using inlib/sg/cube and then the inlib/exlib scene graph logic (and also GL-ES for the rendering).
To build these apps, you need some prerequistes (for example having installed an Android SDK and NDK, etc). See the README on github for instructions on how to build, install and run, but also the "Build for Android" section under the softinex portal for generic instructions. When/if having these two little apps running on your Android device, you can attempt to build the pmx and/or the g4exa apps doing much more visualization in connection to physics.