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.
I love how simple this is, it just gives me an energy score. It’s a really clean interface and the watch complications are really nice. It’s also cheap! I didn’t have to pay a subscription for this, just $5 which is maybe even less than I’d be willing to pay for it. Free trial for 7 days too and you don’t have to give payment info beforehand so you don’t get caught paying a subscription when you didn’t intend to
Developer Response
Thanks for the kind words!I built Circadian Energy as something I wanted to use myself, so keeping it simple with fair pricing was a no-brainer. Glad that resonates. And nice to hear the watch complications are getting some love too. Hope it keeps helping you stay on top of your energy!
New watch face complications for Apple Watch:
- Corner: Energy level with progress bar
- Inline: Energy level with current phase
This brings the total to 4 watch complications.
Enjoy the update.
Version 1.0.9
The developer, Markus Sekulla, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Privacy practices may vary, for example, based on the features you use or your age. Learn More
The developer indicated that this app supports the following accessibility features. Learn More
Supported Features
VoiceOver
Voice Control
Larger Text
Dark Interface
Reduced Motion
Information
Seller
Markus Sekulla
Size
3.3 MB
Category
Health & Fitness
Compatibility
Requires iOS 26.0 or later.
iPhone Requires iOS 26.0 or later.
Mac Requires macOS 26.0 or later and a Mac with Apple M1 chip or later.
