According to IDC, the smartphone OS during Q2,2015 was led by Android who remains the undisputed number 1 with a marketshare of 83% ,and leads by a huge margin as compared to its nearest competitor at 14%.
The number 2 is Apple's iOS with 14%, followed by windows phone with 2.6%
Likewise the next chart ( above this) shows marketshare of smartphone OS as of Q2,2014,during which Android had 76% marketshare .Meanwhile iOS smartphone OS looked strong at that point with almost 20% marketshare However its growth fizzled down and as the first chart shows.