#3 Android

Android is open source mobile platform and Google releases the code under the Apache License. This open source code and permissive licensing allows the software to be freely modified and distributed by device manufacturers, wireless carriers and enthusiast developers. Additionally, Android has a large community of developers writing apps that extend the functionality of devices, written primarily in a customized version of the Java programming language.

All this has helped Android to surpass iOS to become world’s most used mobile platform. Though it may have security concerns when compared to iOS, but let's not forget that it also comes with several more features, including multiple user support, near-field communication, facial unlock and many others.

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