What a 1 hour timer is good for
Long bakes and braises, slow cookers, parking limits, laundry, medication intervals, and 'wake me before the call' reminders when you would rather see a countdown than a clock time.
The countdown runs against your device clock, so it stays accurate if the tab is throttled in the background. At zero it fills the screen with a Stop button, plays your chosen sound, and vibrates on phones. Prefer a clock time instead? Use wake me up in 1 hour.