I see a lot of posts of people using a PS3 Sixaxis controller + app to play games on their Nexus 7. While this is a great idea for those with a PS3 controller lying around, I'm wondering if there is a way to use my Galaxy Nexus as the controller for games on my Nexus 7. I'm doing what I can to avoid buying a new/used PS3 controller for $30+ if I can just use what I already have.