Major features are
Show battery status
Show battery status (Level, Temperature(Cellcius, Farenheit), Voltage...)
Notify when batter is consumed too fast
Notify using "Toast" message periodically
Battery usage history graph
SD card usage (2x1 widget only)
Customizable color & background
1x1, 2x1 widget, notification bar support
As the main design concept is to consume battery power for monitoring as less as possible, estimation time & graph data are not collect real time.
Lite version: Auto-launching when plugged. (please consider this as donation). not every time but per 3~4 hours.
You can find a paid version [Battery Widget Pro].
Recommended by Appgovideo.com (http://www.appgovideo.com/)