A sample application demonstrating how to integrate a LibGdx Android game with Google Mobile Ads SDK (banners and interstitials).
Open source and available on GitHub - https://github.com/TheInvader360
Companion tutorial on the blog - http://theinvader360.blogspot.co.uk
If you benefit from this project, I'd love you leave a comment on the blog and check out my games - https://play.google.com/store/apps/developer?id=TheInvader360