The half-hour is the classic “don’t sit too long” beat: it is the interval ergonomics advice most often points to for standing up, moving, and resting your eyes after a stretch of focused work. Unobtrusive enough to leave running all day and still do its job.
Eight reminders cover four hours out of the box — extend it across a full workday, or trim it to a single focused session. Because it is so easy to ignore until it sounds, it is the one most people leave running from morning to evening.
The interval behind the 20-20-20 eye-rest rule — a beep every 20 minutes, on repeat, to look away from your screen, stretch, or refocus. No account, no install.
A 20-8-2 sit-stand cycle: 20 minutes sitting, 8 standing, 2 moving, on repeat. A beep marks each change. Set the rounds for how much of your day it covers.