Keep your Mac awake. One click.

Doppio lives in your menu bar. Click the cup and your Mac won't sleep; click again and it's back to normal.

Doppio's menu in the macOS menu bar

What it does

Stay awake for an hour, two, indefinitely, or until a time you choose
Stay awake until an app quits, or until a Terminal job signals it's done
Switch on automatically while chosen apps run, or during calendar meetings
Let the display sleep while the Mac keeps working

No account. No data collected. Never goes online.