Worth mentioning that there's still a LOT of people out there using Android v2.3.x http://developer.android.com/about/dashboards/index.html

Also one thing to point out that a lot of people don't realise - all browsers on iOS are still Safari 'under the hood'. App developers are expressly forbidden from attempting to introduce a new rendering engine into their app, so they all have to use the same underlying rendering engine as Safari - only slower because the 'Nitro' JavaScript engine isn't enabled.