Material Design checklist: hiding app bar on scroll?

Per Roman Nurik on Google+ (essentially what @tyczj mentioned)

https://plus.google.com/u/0/+RomanNurik/posts/3G8zYvN5oRC

It's not built in but relatively simple to implement. Just observe scrolling and animate the Y translation. Could also use the "quick return" sample +Nick Butcher​ and I published a few years ago

I believe that example referenced is: https://code.google.com/p/romannurik-code/source/browse/misc/scrolltricks

UPDATE: I also just discovered a great library that does this, along with some other great tricks https://github.com/ksoichiro/Android-ObservableScrollView