Caffeine... I can't do without out on any given morning, so why should my computer? I used Caffeine on my Mac computer before, but this year is the first time that I've worked off of a Mac full-time for my job. I recently remembered the app, and it has been a huge help. The concept is simple, click to give your computer some coffee to keep the screen awake, click again to remove the coffee for it to sleep or dim as normal.
= Screen will go to sleep or dim as normal.
= Screen will stay awake.
If you right-click on the coffee cup, you will see more options, like activating Caffeine for a specific amount of time on your computer.