DashClock is a replacement lock screen clock widget for Android 4.2+. It also exposes additional status items called extensions. The widget comes bundled with extensions that give you instant access to:
To add the widget to your Android 4.2 device's lock screen, simply swipe to the left-most page of your lock screen and touch the "+" icon. Then, select "DashClock" to customize and add the widget. You can make this the primary lock screen widget, replacing the default clock, by first touching-and-holding it and then dragging it horizontally to the very rightmost position.
DashClock is extensible! You can create custom extensions that expose status information using the DashClock API.