Windows Phone 8

Windows Phone 8 was the first version of Windows Phone to be built on the NT kernel, merging Windows 8 and Phone ecosystems into one. It was released on October 29, 2012.

Developer Preview

 * 8.00.9509.20110830-2055
 * 8.00.9543.221.WP8_OSPLAT_DPT_EXT(wpbldlab).20111019-1808
 * 8.00.9571.271.WP8_OSPLAT_DPT_EXT(wpbldlab).20111202-1444
 * 8.00.9592.12.WP8_PD(wpbldlab).20120111-1148
 * 8.00.9618.29.WP8_PD(wpbldlab).20120216-1253
 * 8.00.9622.305.WPMAIN(wpbldlab).20120220-1230
 * 8.00.9628.33.WP8_PD(wpbldlab).20120229-2156
 * 8.00.9646.0.WP8_UXPLAT_DEV_CAM(stevegl).20120324-2128
 * 8.00.9657.365.WPMAIN(wpbldlab).20120403-1543
 * 8.00.9656.16.WP8_PD_DEV(wpbldlab).20120426-0706
 * 8.00.9690.412.WPMAIN(wpbldlab).20120511-1730
 * 8.00.9704.437.WPMAIN(wpbldlab).20120531-1705
 * 8.00.10130.73.WP8_CXE(wpbldlab).20120703-0400
 * 8.00.9735.483.WPMAIN(wpbldlab).20120706-1323
 * 8.00.9805.510.WPMAIN(wpbldlab).20120730-1501

Updates

 * 8.00.10322.71.WP8_CXE_GDR2(wpbldlab).20130408-2128

Apps
Some of these top named apps are available for Windows Phone 8:
 * Facebook
 * Twitter
 * WhatsApp
 * Flickr
 * Vine
 * Kik Messanger
 * Tumblr
 * Skype
 * Google
 * Office
 * Instagram (currently in beta)

Unofficial:
 * Snapchat (Unofficial)
 * Wikipedia
 * 6tag (Instagram Client)
 * YouTube (blocked by Google)