As a software stack, Android has continued upgrading since it was first launched a few years ago. Android includes middleware, operating system and key applications based in Lunix. Android utilizes a special name each time it releases a new version of the platform. The latest version is Android 4.4.2 KitKat, which was released in December of last year. Other versions released previously include Gingerbread, Ice Cream Sandwich and Jelly Bean.

The latest Kit Kat version has enhanced security features and some minor bug repairs. Previous KitKat versions also included the following upgrades: Printing Framework, Hardware Sensor Batching, Storage Access Framework, Full-screen immersive mode, GLES2.0 SurfaceFlinger, Enhancement of the camera on the Nexus 5, New Translucent system UI, and System-wide settings for closed captioning. The first 2 KitKat versions were released in Oct. 31 and Dec. 5, 2013 respectively.

Prior to KitKat versions, Jelly Bean 4.3 was the latest upgrade that Android had. The first Jelly Bean version was released in July 2012 and the last one was released on July 2013. Some of the key features added on the last Jelly Bean Android upgrade were the following: Hebrew and Arabic right-to-left (RTL) support, Bluetooth Low Energy (BLE) support, security and performance enhancements, 4K resolution support, and Bluetooth Audio/Video Remote Control Profile (AVRCP) 1.3 support.

Before Jelly Bean, Android used Ice Cream Sandwich. The first version of ICS was released in June 2011 and the last version ICS 4.0.4. was released in March 2012. Key features included in the latest ICS version were smoother screen rotation and stability improvements.

Gingerbread is one of the first Android versions released. The first one came out in December 2010 and the latest in May 2011. Significant changes in the Gingerbread versions include voice search issue repair, Google Wallet support, improved network performance, Bluetooth repair and Voice chat in Google Talk. Android releases upgrades periodically so users of all systems can stay up to date.