KitKat has been optimized to run on a much broader range of devices, with special focus on the millions of entry-level devices that have as little as 512MB RAM. To help, new APIs have been created, better tools, and better documentation to let you create apps that perform well on all devices.
Check out this video summary of some of the most significant developer features in the latest Android release, including new ways to make your apps beautiful, NFC Host Card Emulation, a printing framework, the storage access framework, low-power step detector and step counter sensors, and more!
Be sure to get the full Android 4.4 API Overview
http://developer.android.com/about/versions/android-4.4.html
And take a look at related DevBytes videos:
https://www.youtube.com/playlist?list=PLWz5rJ2EKKc-2quE-o0enpILZF3nBZg_K
