In Android 4.4 KitKat Google has finally given users an option to quickly and easily switch between home screen launchers. With previous versions of Android users would set the default launcher, use it for awhile, then get tired of it and want to change. That change required digging through Application settings and clearing system defaults. The entire process was far from obvious.
On Android 4.4 KitKat users can now switch between launchers with less than three taps. After installing your first third-party launcher on the new OS, a "Home" setting will be added to the Settings app.
Selecting the Home option will present you with a list of all installed home screen alternatives, and give you the option to activate or delete any of the installed launchers.
One of the methods of Nexus 5's home screen requires users to install a third-party launcher, but with the new Home feature getting Google Now back to the home screen is quick and simple.from the