Apple says that 84 per cent of its users are on iOS 9, its latest software release. By contrast, Android Marshmallow, which has been out since October, is only on eight per cent of Android devices. The need to get more phones updated quicker isn't just a question of getting the newest features. Sure it sucks for developers who want to build for the latest and greatest version of Android, but the more pressing problem was laid bare last year surrounding the Stagefright bug, which let hackers infect Android phones with a malicious text. If you were on a Nexus phone running stock Android, you received critical security updates protecting against the flaw almost instantly. But if you were on any other Android phone, you were left exposed for months.

http://www.smh.com.au/technology/mobiles/google-to-tackle-androids-biggest-problem-but-it-wont-be-easy-20160529-gp6v3x.html