To move an icon on an Android phone, touch and hold the icon, and drag it to a new location. On Android 4.0, this procedure can also make often used icons more accessible by dragging them to the Favorites Tray (located above the Navigation buttons). To reset the Favorites tray, icons can either be moved to make room, or new ones can be stacked with existing icons in the tray (creating a folder).
To move an app from the Favorites Tray, touch and hold the icon and drag it to the home screen (the All Apps icon in the center is permanent, and can’t be moved).
Then, drag the preferred icon to the Favorites Tray. For example–as seen below–the stock browser and contacts icons were moved to the home screen, and replaced with the Dolphin  browser and Gmail.
To create a folder in the tray, drag and stack icons (indicated below with the Gmail and Messaging icons).
Tap the stack and the folder opens on the home screen.
Ease and convenience. What’s not to like?