Android is a mobile operating system(OS). Following are the various versions of OS which has been improved from the first to last:

Android 1.5 Cupcake

Android 1.6 Donut

Android 2.0 Eclair

Android 2.0.1 Eclair

Android 2.2 Froyo

Android 2.3 Gingerbread

Android 3.0 Honeycomb

Android 4.0 Ice Cream Sandwich

Android 4.1 Jelly Bean (API level 16)

Android 4.4 KitKat (API level 19)

The Android Jelly Bean was next to the latest Android OS. The latest one being Android Kitkat which got released in October, 2013.

Android Kitkat is built in order to work on both high end and low end devices. It has improved performance through Low RAM Device API. It has an built-in screen recording, and native Infrared blaster API. It introduces immerse screen mode, which allows more actions through swipe or touch of your finger.

Here are their flavors real life pictures