You're not lazy.
You're on the wrong clock.
Most advice treats everyone the same. ARC finds your chronotype and builds your entire day around your real biological rhythm — so focus, energy, and sleep come naturally.
Tired in a way
sleep doesn't fix?
You've been told you're undisciplined because you can't function at 8:00 AM, or you're wired at midnight. It's not a character flaw — it's your chronotype. Your body runs on a biological clock, and most of us are fighting ours all day.
Mornings feel like fog until 10am
Your cortisol rise is delayed, keeping you in sleep mode long after your alarm.
The 3pm crash every single day
Drinking coffee at the wrong time blockades adenosine receptors, ensuring an afternoon crash.
Wide awake exactly when you need to sleep
Fluorescent lights and digital screens suppress melatonin, pushing your sleep gate back hours.
Your Identity
Which one
are you?
Your chronotype is your body's built-in biological clock. ARC identifies yours in 5 minutes.
Lion
Early RiserEarly riser, peaks before noon, fades by evening.
Read full guide →Bear
Solar RhythmFollows the sun; most of the world runs on Bear time.
Read full guide →Wolf
Night OwlSlow mornings, sharp late — built for the night.
Read full guide →Dolphin
Light SleeperLight, sensitive sleeper with a busy mind.
Read full guide →
Tactical features.
Biological precision.
Your daily protocol
Know exactly what to do, right now. A single focused action for each moment of your day — a live ring counts down your current window. No cluttered dashboard, no guesswork.
Caffeine, timed right
See when your coffee peaks and the exact last safe time to drink it before it steals your sleep. A live decay curve shows caffeine leaving your system in real time.
Morning light window
The single most powerful lever for your rhythm — get light at the right time for your chronotype, and everything downstream falls into place.
Your AI circadian coach
A personal briefing every morning, based on how you actually slept, what you drank, and how your week is trending.
Progress in plain language
Watch yourself get more in sync over time. One clear score, real proof — the deep charts are there when you want them.
Takes 3 Minutes
Find out what's
actually wrong.
Take the Diagnosis
Answer 32 science-backed questions about your sleep, energy patterns, caffeine habits, and lifestyle. ARC builds your full biological profile — the longest onboarding in the category.
Discover Your Chronotype
Find out if you're a Lion, Bear, Wolf, or Dolphin — and what it means for your daily schedule and peak performance windows.
Follow Your Daily Trajectory
Get a live 24-hour protocol with Peak Focus Windows, caffeine decay tracking, sunlight timer toward your 20-min morning target, and smart wind-down notifications.
THE SCIENCE
Built on chronobiology,
not hustle culture.
Your energy isn't random — it follows a circadian rhythm set by light, sleep, and timing. ARC turns decades of sleep and circadian science into simple, personalized actions.
- Sleep Pressure
Adenosine
The Adenosine Clear
Adenosine builds up in your brain from the moment you wake. It creates sleep pressure that makes you feel tired. Caffeine doesn't remove it — it just masks the signal. ARC calculates the exact window to wait before your first coffee, preventing your 2 PM crash.
- Morning Anchor
Cortisol
Cortisol Pulse Timing
Morning sunlight triggers a cortisol spike that sets your entire daily rhythm — including when you'll feel alert and when melatonin will rise 12–16 hours later. ARC gives you a precise sunlight window within minutes of your wake time.
- Sleep Onset
Melatonin
Digital Sunset Protocol
Melatonin release is triggered by your morning cortisol spike and suppressed by evening light. ARC's Digital Sunset protocol tells you exactly when to dim screens and lights to let your natural sleep signal rise — every night.
Sample Biological Briefing
“Strategic window. Waiting 90 mins after waking prevents your 2 PM focal crash.”
ARC delivers context-aware coaching in plain language — with the science behind every action, not just a to-do list.
Research Foundation
Dr. Andrew Huberman
Stanford Neuroscience Lab
Light exposure, cortisol rhythms & adenosine management
Dr. Matthew Walker
UC Berkeley Center for Sleep Science
Sleep architecture, circadian cycles & melatonin optimization
Trusted by sleep seekers
& peak performers.
“Nice to know how my body works — the optimal time to drink coffee and when to cut it off so it doesn't affect my sleep.”
“As a night-shift software engineer, ARC is the only circadian app that actually supports inverting guidelines safely. Absolute game changer.”
“The caffeine decay tracker is scarily accurate. My sleep quality score shot up 40% after shifting my cutoff window.”
Sound Familiar?
Built for people who are
done guessing.
High-Performers
Founders, engineers, and creators who need maximum focus hours. ARC maps your peak windows so you stop guessing.
View Guide →Coffee Drinkers
You drink coffee every day but have never understood how it actually interacts with your sleep. ARC shows you the exact cutoff minute.
View Guide →ADHD Professionals
Structured visual missions replace overwhelming to-do lists. Biology-aligned triggers your brain actually responds to.
View Guide →Sleep Seekers
Sleeping 7-8 hours but still exhausted? It's a timing problem, not a duration problem. ARC fixes the root cause.
View Guide →Biohackers
Real data and correlations — not just streaks and checkboxes. Understand the cortisol-melatonin rhythm driving your entire day.
View Guide →Shift Workers
Design your flexible schedule around biology, not just calendar availability. Anchor your rhythm regardless of when you wake up.
View Guide →
PRICING
Start syncing
today.
Subscription auto-renews, cancel anytime. Managed through the App Store.
Weekly
$4.99/ weekGet Instant AccessCancel anytime
Annual
Most Popular$39.99/ yearGet Instant Access~$0.58 / week • Save 88%
Have questions or a tight budget?
Whether you want to understand the science better, or you're a student experiencing financial hardship, we don't want price to be a barrier to your health.
Payment charged to Apple ID at purchase confirmation. Subscription auto-renews unless canceled 24h before end of period. Manage in App Store account settings.
FAQ
Questions
answered.
What's a chronotype?
Your body's natural timing type — when you're wired to sleep, wake, and peak. ARC sorts you into one of four (Lion, Bear, Wolf, Dolphin).
Do I need a wearable?
No. ARC works from a few simple inputs and gets smarter as you log.
Does it work for shift workers?
Yes — there's a dedicated night-shift protocol that inverts the guidance safely.
Will it wake me up / is it an alarm?
No. ARC is a coach, not an alarm clock — gentle, well-timed nudges you fully control.
Is my data private?
Your data stays on your device. See our Privacy Policy.
How do I cancel?
Anytime, through your App Store subscription settings.
START TODAY
Stop fighting
your clock.
Find your chronotype and build a day that works with your biology.
Download on theApp StoreFree to download · Cancel anytime · No commitment