I have a confession to make: I'm a system stat whore. Not just on my PCs, either - I want to know what's up on all my devices, all the time. I've been using OS Monitor on my tablets for quite a while now, and while the information it provides is useful, it doesn't encompass all of the info that I wanted to see at a glance. Furthermore, it doesn't offer support for quad-core devices like the Transformer Prime.
On Android, there are plenty of ways to monitor your processor, battery, RAM usage, etc. However, there is really no way to monitor said information while continuing to do other tasks, since Android only allows one window in the foreground at a time. That's where Cool Tool, a simple resource monitoring app, comes into play.
Cool Tool is different than other resource monitors on Android because it has an option to stay on top of other windows or the notification bar, allowing you to constantly monitor your hardware statistics.