Produced by Samsung Electronics, the Samsung Galaxy S4 is an Android smartphone first unveiled in March 2013 and released in stores in April 2013. It is the successor to the Galaxy S III, but features upgraded hardware and an increased focus on software features that take advantage of the hardware capabilities.
These include the ability to detect when a finger hovers over the screen and expanded eye-tracking functionality. The S4 is also slightly lighter and narrower than the S III. It ships with Android operating system 4.2.2 and Samsung’s TouchWiz Nature user experience. Head tracking features and “Smart Scroll” and “Smart Pause” functions have also been extended on the S4.
Upon its release, the Samsung Galaxy S4 became the fastest-selling smartphone in Samsung’s history, selling 20 million units worldwide in the first two months. By October 2013, Samsung sold more than 40 million units.