ARC: Circadian Rhythm & Sleep

Your body already knows when to sleep. ARC helps you hear it.

THE LIVE CAFFEINE FORECAST NO OTHER APP HAS

Log your morning espresso. Watch the 12-hour decay curve update in real time on your home screen. See your mg level rise and fall hour by hour, with a clear sleep-safe threshold line. Know the precise minute it's safe to sleep tonight.

Most people are sabotaging their sleep every single day — and don't know it.

WHO ARE YOU?

Lion. Bear. Wolf. Dolphin. ARC's chronotype diagnosis identifies your biological wiring — the reason mornings feel impossible, or why you come alive at 10 PM. Then it builds your entire day around it.

Built for the 73% who don't fit a generic 9-to-5 — including night owls, DSPD, and shift workers.

YOUR DAILY PROTOCOL

ARC's home screen shows you one thing: what to do right now.

SUNLIGHT TIMER Track morning light exposure toward your 20-minute target. Sets your cortisol rhythm for the next 16 hours.

LIVE CAFFEINE FORECAST Log every drink. Watch the 12-hour decay curve. Know your wall — the last safe coffee before it starts cutting your deep sleep.

PEAK FOCUS WINDOWS Your hardest work, scheduled at your chronotype's natural cognitive peak.

WIND-DOWN SEQUENCE Melatonin begins 14–16 hours after your cortisol peak. ARC times the signal so you don't have to think about it.

NUDGES THAT KNOW WHO YOU ARE

Wolves get notifications written for late-night focus. Lions get protocols built for early bedtimes. Night-shift workers get the entire schedule inverted. No two chronotypes get the same nudges.

"Wolves hit their real peak at 6 PM. Use this window for your hardest work."

"Caffeine wall — every cup after this costs you 15-20 minutes of deep sleep."

"Start winding down — your delayed melatonin needs the signal early."

Written for your chronotype. Never generic, never annoying.

BUILT ON REAL SCIENCE

Based on protocols from Dr. Andrew Huberman (Stanford) and Dr. Matthew Walker (UC Berkeley). Circadian rhythm research won the Nobel Prize in 2017. Your internal clock controls everything — when you're sharp, when you crash, when you should sleep.

Try ARC Pro, Cancel anytime before your trial ends and you won't be charged.

SUBSCRIPTION PRICING

ARC Pro is available as: • Weekly: $4.99/week • Monthly: $9.99/month • Annual: $34.99/year (Best Value — Save 86% vs weekly)

Payment will be charged to your Apple ID account at confirmation of purchase. Subscription automatically renews unless canceled at least 24 hours before the end of the current period. Manage or cancel anytime in your App Store account settings.

Privacy Policy: https://www.notion.so/Privacy-Policy-for-ARC-Sync-Your-Life-2f2af72016c9802bace6fddd4a1ed526

Terms of Service: https://www.notion.so/Terms-of-Service-for-ARC-Sync-Your-Life-2f2af72016c980c8be7be0bacf1ee076