eclipse/ has the examples that eclipse can load (no longer updated). Otherwise, in andriod studio.
basicARDemo a "simple" example that turns on the camera and displays sensor info like gps over the image. It was always intended to be a simple demo.
ARCoreSimpleDemo is a "simple" example using google's ARCore modules. see https://developers.google.com/ar/ and much of the example is taken from googles hello_ar_java example in https://github.com/google-ar/
These are example code for University of Wyoming, Cosc 4730 Mobile Programming course and cosc 4735 Advance Mobile Programing course. All examples are for Android.