Circadian Rhythm & Sleep: ARC

Circadian Rhythm & Sleep: ARC

Energy, Caffeine & Body Clock

8 ratings
4 reviews
Free
In-App Purchases

Details

Released
February 5, 2026
Updated
October 30, 2026

Features

Circadian Rhythm & Sleep: ARC video #1 for iPhone
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About

This app analyzes your personal energy patterns to create a customized daily plan. It helps you understand your body's natural rhythms for optimal energy, focus, and well-being. Features include personalized caffeine cutoff times and adaptive daily adjustments.

✓Personalized daily energy plan
✓Calculated caffeine cutoff times
✓Adaptive daily adjustments
✓Energy dip tracking and analysis
✓Short-term habit experiments
✓Educational briefings on sleep and timing
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What's New in Circadian Rhythm & Sleep

2.0.2

October 30, 2026

• Your energy dip now follows your own pattern, so the label, plan and walk agree • Bedtime and wind-down stay at the times you set • Opening the app late no longer shifts your morning • Late sleepers see the right plan after midnight • "Afternoon dip" is now "Energy dip"

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Subscriptions & In-App Purchases

ARC Yearly Pro

Unlimited access to all circadian protocols

$49.991 Year
Price Updates
October 31, 2026→$49.99
August 6, 2026→$39.99
May 30, 2026→$29.99
How to cancel Circadian Rhythm & Sleep subscription ⁉️

User reviews

Very strong subscription binding!

The autumn application strongly imposes its paid

Subscription, which has a very negative impact on the experience of using the application.

5 Stars for Potential

I’m giving this five stars for potential and because it serves a niche in the market that is very much needed. However, it is a bit off for me. I’m a wolf type. Already knew that. Being a wolf type my lifestyle is already built around my DSPD so my schedule does not configure to your typical 9-5. That being said, the app quiz still forced me to answer questions about peak energy and coffee timing based on a 9 to 5 schedule. I thought the whole idea of this app was that I would not have to answer questions as though I have a typical schedule. So for some reason, it thinks I have my first coffee at 3:30 AM, which is an hour before I told it I usually go to sleep. Seems like a bug? I also would like the ability to switch from UK (military) time to U.S. time.
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Response from developer

You're 100% right, and we fixed all three. The 3:30 AM coffee bug was a hardcoded "AM" that ignored your actual wake time. The quiz now uses relative timing ("a few hours after waking") instead of fixed clock times. And we've added a 12h/24h toggle in Settings. Rolling out in the next few hours. Thanks for flagging these. Wolves with DSPD are exactly who ARC should serve best.

Know your body!

I must say I didn’t pay much attention to my circadian rhythm but it’s nice to know about how my body works and also what the optimal time it is to drink coffee and when to cut it off so it doesn’t affect my sleep. It’s a good little reminder to help stay in tune with your body!

Response from developer

Really glad that it helped you in your busy life. Keep your circadian rhythms healthy and enjoy ✌️

Essential for a night shifter

As a night shifter trying to stay consistent has its ups and downs, where this maps out your day, when you shouldn’t have anymore caffeine and such to try and optimize your circadian rhythm. This isn’t JUST for night shifters and it’s for everyone. Even if you are on a standard 9-5. It helps people create better habits for longevity of a circadian rhythm.
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Response from developer

Thank you so much for this so positive review

Developer apps

FAQ

What is ARC?

ARC is a wellness app designed to help you understand your body's natural energy patterns and create a personalized daily plan. It focuses on your circadian rhythm to optimize energy, focus, and sleep.

How does ARC calculate my caffeine cutoff time?

ARC calculates your last safe coffee time by considering your bedtime, your personal caffeine metabolism rate, and all the caffeine you've consumed that day. This provides a precise cutoff tailored to you, not a general rule.

Does ARC require an account or wearable device?

No, ARC does not require an account, login, or wearable device. Your history is stored locally on your phone, and it does not request location access.

What kind of data does ARC track?

ARC tracks your energy peaks and dips, caffeine consumption, and the impact of habits like light exposure and walks. It uses this logged data to build your personalized plan and provide insights in the Trends tab.

How often is ARC updated?

The latest version of ARC is 2.0.2, and it was last updated on October 30, 2026. This indicates regular updates to improve functionality and features.

What are the subscription options for ARC Pro?

ARC Pro offers weekly ($4.99), monthly ($12.99), and annual ($49.99) subscription plans. The annual plan includes a 7-day free trial.

Is ARC suitable for children?

ARC has an age rating of 4+, making it broadly accessible. However, its focus on complex biological rhythms and detailed logging may be more relevant for older users.

What does ARC not do?

ARC explicitly states it does not provide sleep scores, streaks, badges, or congratulatory messages. It focuses on factual insights and practical adjustments rather than gamified motivation.