Roboto: Google’s signature font is now open source
Also worth take a look at the Roboto specimen booklet which presents the font in a better light than the Google Fonts website (PDF): <a href="http://material-design.storage.googleapis.com/publish/material_v_3/material_ext_publish/0B0J8hsRkk91LNGdYTEF0VnVPT0k/RobotoSpecimenBooklet.pdf" rel="nofollow">http://material-design.storage.googleapis.com/publish/materi...</a>