Android "Jelly Bean" is the name given to three major point releases of the Android mobile operating system developed by Google, spanning versions between 4.1 and 4.3.1. The first of these three, 4.1, was unveiled at Google's I/O developer conference in June 2012, focusing on performance improvements designed to give the operating system a smoother and more responsive feel, improvements to the notification system allowing for "expandable" notifications with action buttons, and other internal changes. Two more releases were made under the Jelly Bean in October 2012 and July 2013. As well as 4.2 which included further optimizations, multi-user support for tablets, lock screen widgets, quick settings, and screen savers, and 4.3 which contained further improvements and updates to the underlying Android platform. With over 1 million applications in the Google Play store, Android now can finally say that it has the largest app catalog, bigger than Apple and needless to say multiple times bigger than Windows Phone. Android 4.3 makes it possible for developers to bring really console-grade games with support for Open GL ES 3.0 graphics and many under the hood improvements in the way the system handles visuals. It is adding tons of possibilities for accessory makers with Bluetooth Smart and Low Energy support. It is opening a new realm for those that want to implement location in their apps with hardware. Jelly Bean's interface reflects a refinement of the "Holo" appearance introduced by Android 4.0. The default home screen of Jelly Bean received new features, such as the ability for other shortcuts and widgets on a home screen page to rearrange themselves to fit an item being moved or resized.
The notification system was also improved with the addition of "expandable" notifications; individual notifications can now display additional content or action buttons (such as "Call back" or "Message" on a missed call), accessible by dragging open the notification with a two finger gesture. Notifications can also be disabled individually per-app. Android 4.2 added additional features to the user interface; the lock screen can be swiped to the left to display widget pages, and swiped to the right to go to the camera. A pane of "quick settings" toggles which is a feature seen in OEM Android skins was also added to the notification area accessible by either swiping down with two fingers on phones, swiping down from the top-right edge of the screen on tablets, or pressing a button on the top-right corner of the notifications pane. The previous browser application was officially deprecated on 4.2 in favor of Google Chrome for Android. 4.2 also adds gesture typing on the keyboard, a redesigned clock app, and a new screen saver system. Android 4.2 also supports multiple users on tablets.
Android 4.3 consisted of further low-level changes, including Bluetooth low energy and AVRCP support, SELinux, OpenGL ES 3.0, new digital rights management (DRM) APIs, the ability for apps to read notifications, a VP8 encoder, and other improvements. Android 4.3 also included a hidden privacy feature known as App ops, which allowed users to individually deny permissions to apps. However, the feature was later removed on Android 4.4.2; a Google spokesperson stated that the feature was experimental and could prevent certain apps from functioning correctly if used in certain ways.

ITT TECHNICAL INSTITUE
SD1430
Introduction to Mobile Operating
Systems
Onsite Course
Assignment 4: Android 4.3 vs 4.2

Reference

H., V. (2013, July 25). Android 4.3 Jelly Bean: All the new features. Retrieved November 10,
2014.
Dennis, J. (2013, September 20). What Are The Biggest Improvements In Android 4.2 and 4.3?
Retrieved November 10, 2014.