Don’t you just hate it when you are watching a long video, or having a skype chat on your mac, and the screen totally goes dim after a couple of minutes! You don’t want to change your settings because most of the time you want your mac to behave like that!
Caffeine was recommended to me by a friend and was my first download when I recently checked out the mac app store for the first time.
The app puts a little coffee-cup icon in the top right hand corner of your screen and if you want your screen to stay on for a particular task, all you have to do is click the coffee cup to activate the software.
Sometimes its the simple things that are most effective and helpful!