Peek-a-Boo is an alternative to your Mac's Activity Monitor, yet apart from its throb window it doesn't offer much more. Thanks to its cumulative information window you can easily compare the CPU usage of each application. Clicking on one will bring up a process information window for the particular application with memory usage and the full command, but not much more.
The CPU usage history is something that already exists in the Activity Monitor, but it's a useful tool to see when an application has shot up in memory usage. Users will also find the logging information window, with its listing of common processes, of some use.
As I've said before, the real feature that sets Peek-a-Boo apart from the Activity Monitor is the Process Throb View. It allows you to see all processes in real time, in a sort of graph view. Processes appear and disappear as they become active or inactive in real time. The bigger the icon, the bigger the process. You'll also notice every item is constantly in movement, reflecting the constant movement going on under the hood of your Mac.
Peek-a-Boo is a traditional activity monitor for Mac, with a fun Process Throb View.