My side project, DashClock, is now open source and live on Google Play!
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:
• Your current local weather
• Missed calls and unread text messages
• Your next calendar appointment
• Unread Gmail inbox or priority inbox conversations
• Your next scheduled alarm
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.
Developers: The project is open source at http://code.google.com/p/dashclock, and if you want to write custom extensions, there's an API! Visit the open source project for more info.