CPU Usage Overlay is the quickest way to check your CPU usage. Simply tap the widget and a process list will be overlaid on top of your screen. This allows you to view your cpu use as you go about using your apps.
This widget is a shortcut to the "Show CPU Usage" option under Settings->Developer Settings. It works by starting the same service that Developer Settings launches. As a caveat, this widget will not work on any device that does not already support showing cpu usage.
Note: This is only a widget. Therefore, you will need to go to the *Widgets* section of your launcher and drag it to your homescreen in order to use it.
Keywords: CPU Usage, Cpu Monitor, Task Monitor, Task List, Show CPU