CPU Usage Widget monitors your CPU and displays a real-time visualization per core. Included is also an app to see a "top list" breakdown of processes sorted by CPU usage to find out what is consuming your resources as well as an app to define the widget settings (colors update interval).

Instructions:

1. Install the app
2. Select the widget (for example long-pressing in your list of widgets)
3. Place the widget accordingly on your home screen
4. The settings are opened; set up your colors and the update interval then press save
5. The widget should now appear on your home screen
6. Long-press the widget to resize
7. Press the widget to see the process list

Please also check out Network Widget for Android:

http://play.google.com/store/apps/details?id=com.rtsw.androidnetworkwidget