Jiggler

Jiggler is a fantastic freeware utility that is intended to prevent sleep and screensavers from interrupting the tasks you are performing on your computer. You no longer need to keep changing your sleep and screensaver settings in System Preferences. All you need to do is install Jiggler, and it will do the job for you by jiggling your mouse periodically.

The sole aim of Jiggler is to ensure your Mac stays awake. When you have long tasks to execute on your computer, it can be frustrating to have to disable the screensaver and sleep timer only to switch them back on once you're done. The "never sleep" corner does not help as it doesn't prevent your machine from falling asleep. However, Jiggler is a small helper that occasionally jiggles your mouse to keep your machine alert.

With Jiggler, your machine continues to function without interruption. The application only wiggles your mouse from time to time, ensuring your machine stays awake and happy. You can choose to run it when you want to stay awake, and quit it when you don't need it. Additionally, you can set the application not to wiggle your mouse unless your computer has been idle for a specific period, meaning you can keep Jiggler running in the background while you work without being disturbed.