Circadian Energy

Shows when you have energy today and when your next peak is coming. Calculated from your sleep, HRV, and workouts. Science-based, not guesswork.

Circadian calculates your personal energy curve for the day. Based on your sleep, heart rate variability, and workouts, the app shows you when you're fit today and when your next peak is coming.

YOUR ENERGY CURVE The curve is based on the two-process model of sleep research (Borbély, 1982) and is personalized with your real HealthKit data. Not a generic daily rhythm, your individual energy. What feeds in:

• Sleep amount and sleep quality from last night
• Heart rate variability (HRV) and resting heart rate
• Workout impact on your energy level
• Sleep debt from the last 14 days
• Chronotype detection (early bird, normal, night owl)
• Daylight exposure and wrist temperature

SLEEP WINDOW Circadian recommends your optimal bedtime and wake-up time based on your energy curve and your personal sleep needs.

WIDGETS See your current energy level right on your home screen or lock screen. Also available on Apple Watch.

APPLE WATCH Your energy level at a glance, right on your wrist. 4 complications for your watch face: Circular, Rectangular, Corner, and Inline.

PRIVACY All health data stays on your device. No account, no cloud, no tracking.

ONE-TIME PURCHASE Try free for 7 days with all features. Then unlock once. No subscription, no hidden costs.