Google Releases Android 5.1: Latest Android Lollipop Update Includes New Security Features, HD Voice
Google Inc. released the Android 5.1 update Monday, a new version of its Android Lollipop operating system that fixes a number of problems with earlier releases and includes a few new tricks. Google is rolling out the update now for the Nexus 4 and Nexus 5 smartphones, as well as the Nexus 7 tablet.
Story added 10. March 2015, content source with full text you can find at link above.