Google is serious about revamping Android to look more modern, but most of the apps we spend our days in are still stuck in the past. With a little friendly encouragement, maybe developers can make the transition more quickly. Google has posted a checklist of material design elements on the Android developers blog, and it's quite extensive.
The checklist covers everything from tangible surfaces to how apps should implement tabs. There are a number of nifty little animated GIF examples, along with plenty of links to the developer documentation and sample code.