SunSync vs Seize Light

Always tired, waking groggy, or struggling to fall asleep? The cause might be simpler than you think — your morning light routine. SunSync syncs your day to the sun. Track sunlight exposure, estimate your vitamin D intake, and get personalized circadian rhythm guidance — all based on your real location and habits. Your body clock controls your sleep, energy, mood, and focus. SunSync helps you work with it — not against it. With SunSync you can: - Track sunlight exposure and daily light habits — know when you've hit your target - Estimate vitamin D from sun exposure based on your skin type and location - Log supplements and monitor your total daily intake - Follow personalized circadian recommendations for your schedule - Discover your best sunlight windows — and when to avoid the UV index - Build routines to improve sleep and melatonin production naturally - Set smart reminders for sunrise, sunset, and wind-down time - Add a home screen widget — see your vitamin D window at a glance, without opening the app - View history and long-term trends to see your progress Built for the biohacking community — and anyone who just wants to feel better. Whether you're optimizing for performance or simply tired of being tired, SunSync gives you the sunlight data your wellness routine has been missing. Vitamin D tracking, body clock alignment, supplement logging, and a home screen widget showing your vitamin D window — in one app. Disclaimer: SunSync provides estimates and general wellness guidance. It is not a medical device and does not replace professional medical advice. Terms: https://martarodriguezm.github.io/SunSyncLegal/terms.html Privacy Policy: https://martarodriguezm.github.io/SunSyncLegal/privacy.html

Get the right light at the right time. Seize Light reads where you are and the sky above you, computes the sun's real position on your device, and shows your daily light windows — when to get outside, and when to wind down. Most sun apps just show today's UV number. Seize Light shows your two windows: a morning-light window to help set your body clock, and the vitamin-D window — the part of the day the sun is high enough to make vitamin D — plus an evening wind-down that tells you when to dim the lights. Your Apple Watch's Time in Daylight turns it into a passive daily habit, with a transparent Light Score and a streak. YOUR THREE WINDOWS • Morning light — get outside soon after waking to help set your clock; today's target minutes adjust for cloud cover. • Vitamin-D window — opens when the sun is high and UV is strong enough, and closes when it isn't (it tells you why). Keep it short and sub-erythemal. • Evening wind-down — when to dim the lights as part of a wind-down routine. THE LIGHT SCORE A simple, transparent 0–100 score from three parts — morning light, daylight total, and evening protection — fed by your Apple Watch's Time in Daylight. Missing data is never held against you. Build a daylight streak and watch your 90-day trend. EVERY NUMBER IS CITED The solar math, the UV model, and the vitamin-D estimate all trace to published science in an in-app "How this works" screen. HONEST BY DESIGN • UV comes from weather-forecast data (Apple Weather), not a sensor. • Vitamin-D output is an estimate from a model, not a blood test. • Sun safety first: protection is advised at UV 3+, and the rule is always — don't burn. • General wellness and educational use only — not medical advice. Consult a healthcare professional before making health decisions. PRIVATE BY DESIGN • No account. No sign-up. • The solar and vitamin-D math run on your device; only coarse coordinates are sent, for the weather lookup. • Health data is read-only and never leaves your device, except to sync through your own private iCloud — and it is never used for advertising. Weather data provided by Apple Weather. Carpe lucem. Seize the light.