The folks at XDA-Developers Forum know that Android fans can't wait any longer to feast on Google's latest OS release, so XDA user geoworld_200 has extracted the launcher from Android 4.4 and posted it for anyone to download . Stripped from the Nexus 5, the launcher brings the home screen and app drawer from KitKat to devices running Android 4.1 Jelly Bean and up. You can even use touchless search from the home screen by saying "Ok, Google Now." Here's how to get your device skinned with the brand new KitKat look and feel.
1. Enable third-party app installation by checking the Unknown Sources box under Security in Settings.
2. Download the 25MB launcher package. It's a Zip file, so you'll have to extract the three APKs on your computer and copy them to your device. You can also download the package on your phone and extract the APKs using third-party apps such as Unzip.
3. Install the files on your phone in this order: PreBuiltGMSCore.apk, Velvet.apk then GoogleHome.apk
4. Open the launcher.
Now you have the cool new Android 4.4 KitKat experience on your Jelly bean device. You get a fresh new interface that gives you access to your wallpaper, widgets and settings with just a long-tap, and other great features.
You'll still be able to use your regular Jelly Bean home screen if you prefer, by selecting the relevant launcher when you hit your home button.