Roboto
Roboto is a sans-serif typeface family introduced with Android Ice Cream Sandwich operating system. Google describes the font as "modern, yet approachable" and "emotional". The font is licensed under the Apache license. The entire font family was officially made available for free download on January 12, 2012 on the newly launched Android Design website. The family includes regular and oblique styles of Thin, Light, Regular, Medium, Bold, Black, and Condensed widths.
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