About this app
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.
Latest release
What’s New
- New Trends view: compare today's energy curve against any past day or date range. - Optional notifications in the morning and evening. - Insight right under the curve on the Dashboard: explains what is shaping your curve the most today. - Smaller bug fixes that could occasionally make the curve sit too high. Enjoy the update.
Audience growth
Ratings growth
Baseline captured. Growth appears after the crawler observes a changed rating count.
Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.
Price tracking
Price intelligence
First snapshot captured. The trend line starts after the next crawler price observation.
- First observed Sep 4, 2026 · 2:39 AM Free