Home Screen Personalization -
When you're personalizing your home screens in Jelly Bean, you'll notice that when you place a widget on a home screen, the other items on that screen will automatically move around to make room. Widgets are also manually resizable. When necessary, Jelly Bean will automatically resize a widget as well, so that it fits within a home screen that may be littered with other items. You can also remove apps and widgets from a screen quickly, by pressing and holding then flicking them off the top of the screen.
Click to enlarge
Improved Text and Language Input -
Google has also updated Android's dictionaries to be more accurate and relevant to users. Jelly Bean uses a language model that adapts over time and also features improved text-to-speech capabilities that work even if you don't have a data connection. When composing messages, the keyboard found in Jelly Bean will try to guess your next word before you start typing. Once accustomed to the new predictive algorithms, entering text can be much faster.
Sharing & Pairing -
Thanks to Android Beam, Jelly Bean devices can also share photos, videos, contacts, web pages, apps, and more using a simple tap. When you touch two NFC-enabled Android devices back-to-back, you'll get the option to beam content from your screen to a friend.
You can also pair your Jelly Bean device with other devices such as your Bluetooth headset or speakers by tapping them together, provided the Bluetooth device supports the Simple Secure Pairing standard. This functionality eliminates the need to sync or search for devices and then connect them manually.
That's Not All -