Android has surpassed Windows as the largest share of web traffic[0], though maybe that means those social apps like Instagram, Facebook, etc. Stat counter also states that >35% of web browser traffic is mobile not desktop[1].

[0] http://gs.statcounter.com/press/android-overtakes-windows-fo...

[1] https://en.wikipedia.org/wiki/Usage_share_of_web_browsers#/m...