#3 BlackBerry 10 OS

BlackBerry 10 OS is the latest offering from BlackBerry Ltd (it was Research In Motion previously), and it got shipped with the company’s flagship phone ‘BlackBerry 10.”  

The features shown off at the BlackBerry World conference included a unique platform-wide flow interface, a new intelligent keyboard, as well as a camera app which allows the user to adjust the photo or individual faces by moving through time scale to optimize picture quality (it gave the time machine feel to the users)

The user interface also includes the ability to run 8 "Active Frames". Active Frames are applications that are currently running within the operating system, but minimized and showing a feed of live information on the home screen. The Operating System also features the 'Hub', a list accessible from anywhere in the OS where all notifications including emails, social networking sites and text messages in one complete list.

Read also: 10 Most Frustrating Things About Being A Programmer and 7 Most Valuable Tech Brands Of 2013