After Google I/O, I started to study about Material Design, the awesome and new design guideline that Google did to unify mobile and web visual languages. And it's awesome, congratulations to the Google's design team.
These icons were originally made by Google and it's a part of the system iconography style, which has a different approach comparing to Holo, but it's clean and I think that works great on Android too. There's a lot of stuff to cover, but I'm already loving it.
All these icons were made with Sketch, by the way. <3