Wake Up is a very simple utility that pokes the display every so many seconds to keep the Mac from going to sleep.
The User decides how many seconds between pokes using a drop-down menu (Let Me Sleep plus one to ten minute settings). The seconds are counted down and displayed in the Control Panel's top right corner. When the countdown reaches zero, the cursor is moved to the Control Panel and the mouse is tapped (simulating the User clicking on the Control Panel).
The Control Panel includes a checkbox to pause the countdown.