Circadian: Sleep & Energy

Plan your day with your energy curve, find your sleep window and set a smart alarm. With widgets for iPhone and Apple Watch. No subscription.

Plan your day around your sleep rhythm. Circadian estimates your daily energy pattern from sleep, heart rate variability and activity to help you find times for activity and rest.

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. The curve is a model-based estimate. 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 a bedtime and wake-up time based on your energy curve and your personal sleep needs.

SMART ALARM Choose a personal wake window. Circadian selects a wake time within it based on your calculated energy curve. You can also set up optional waking on your Apple Watch.

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.