Lots of Macs apps like to eat up CPU power and battery life. Coolant is a simple little app that alerts you when an app starts eating into your CPU and overheating your Mac.
Once Coolant is set up, it will send you a notification when an app starts killing your CPU. Click the alert and you're taken over to the built-in Activity Monitor. It's simply, but it's a handy tool for laptop users. It's a pretty pricey at $US9.99, but you can check out a free trial to help you decide if you're interested in it.