Smart Scroll is one of the brand new features that comes built into the Samsung Galaxy S4. It enables the S4 to scroll down pages, such as webpages or email messages, without you having to touch the screen. Just look at the screen and tilt, and the page will scroll up or down.
Well, it makes reading easier and more flowing! How about if you're reading a long article and you're stuck on the bus and only have one hand on your phone? It'll just scroll down as soon as you tilt the screen. It's also perfect if you're scanning a document. You won't have to keep swiping the screen to go down the page, just tilt the phone. Or, if you're showing someone your Facebook feed or an email, Smart Scroll will keep on scrolling, making the reading process on the Samsung Galaxy S4 that little bit nicer.
Once you've turned on Smart Scroll, which is an option in the Settings menu, the front facing camera on the S4, along with the gyroscope sensor & top secret software, will work together to track your eyes and work out when you've tilted the phone. When it recognises both of those things it scrolls the page or email down straight away so you can keep reading seamlessly, without having to keep touching the display.