At the bottom of every screen is an area called Favorites Tray. The Favorites Tray is like a dock for your home screen: The shortcuts or folders placed there stay put as you swipe from one screen to the next. This area is for you to place shortcuts to your favorite and most used apps, widgets, books, magazines, movies, and music icons for faster access.
To add an icon to your Favorites Tray, first touch and hold an icon you do not want in the tray and move it out of the tray. Touch and hold an icon you do want in the tray and drag it into an available slot in the tray. Once you release the icon, it stays put.