The Nexus 4 (codenamed Mako or Occam) is a smartphone co-developed by Google and LG Electronics that runs the Android operating system. It is the fourth smartphone in the Google Nexus series, a family of Android consumer devices marketed by Google and built by an original equipment manufacturer partner. Unveiled on October 29, 2012, and released on November 13, 2012, the Nexus 4 succeeded the Samsung-manufactured Galaxy Nexus. As with other Nexus devices, the Nexus 4 was sold unlocked through the online Google Play store, but was also made available at retail by wireless carriers. Based upon the hardware of the LG Optimus G, the Nexus 4 was distinguished from its predecessor by a quad-core Snapdragon S4 Pro processor, an 8 megapixel rear camera and 1.3 megapixel front camera which use the Sony BSI sensor, Qi wireless charging, and the introduction of version 4.2 ("Jelly Bean") of Android – an update to the operating system which introduced: 360° spherical photo stitching called "Photo Sphere"; a quick settings menu; widgets on the lock screen; gesture typing; and an updated version of Google Now.