Sway

Sway lives in the menu bar and counts down to your next break, with a heads-up popover before each one. When a break starts, it fades a full-screen overlay onto every display, shows the logo filling up as the break runs, and offers snooze buttons and a skip button after five seconds. Optional extras include blink and posture nudges, planned breaks at fixed times, longer breaks every few breaks, work hours and a pause after 30 seconds without input. It suits people who want a gentle reminder to stand up rather than a timer they can click past.

The README says it needs macOS 13 or later and is universal, for Apple silicon and Intel. It is not notarized by Apple yet, so macOS blocks the first launch until you allow it in Privacy & Security or clear the quarantine flag in Terminal. The interface is available in several languages, and the README says the app is free and MIT licensed.