Tetra Lockscreen app which is part of Microsoft Garage project got updated to v220.127.116.11 in Windows Phone Store. This a minor update which includes support for additional toast icons and minor bug fixes.
Widgets supported so far:
+Displays upcoming calendar events
+Visualizes the pace of your day with a simple timeline
+Shows your current location on a street map
+Displays nearby calendar events with identifiable locations
+Pan and zoom in the top area of the screen, the bottom is reserved for unlocking
+Displays activity in steps, distance or approximate number of calories burned
+Compare by hour in the daily view, or by day in the weekly view
+Keeps time even when your screen is off
Download it here from Windows Phone Store.