well, Nowdays the technological trend development is proceeding forward with great speed. And in this trend Both the iphone(ios) and the android phones are well functioned in its own way. if you start comparing in both ios and android phones then it will be quite difficult to pick out any of them .But, From the history of phones development,obviously, IOS is superior and sustainable. It'll be quite difficult to say which one is going to take over other.
Thank you