D3-Sync: Sun & Supplements

New: Live Activities for active sun sessions, Apple Watch ring, and a privacy-first design.

Track your daily Vitamin D3 from sun exposure and supplements — privately, on-device.

D3-Sync estimates how much Vitamin D you synthesize while you're outside, based on your skin type, the local UV index, and how much skin you have exposed. Add supplements with one tap. See your daily total on the dashboard, home-screen widget, Lock Screen widget, Apple Watch, and the Live Activity / Dynamic Island during active sun sessions.

FREE FEATURES • Real-time UV index for your location • Manual supplement logging in IU • Daily progress ring with goal • Small home-screen widget • Apple Watch progress ring + supplement logging • Apple Health integration (read & write Vitamin D)

PRO (subscription or lifetime) • Active sunbathing timer with sunburn-prevention safety • Live Activity & Dynamic Island for live sessions • Passive background tracking (no timer required) • Smart sun-window alerts using forecast UV • Lock-Screen widgets and the medium home-screen widget • Apple Watch UV insights and advanced complications • Weekly & monthly trends with Apple Health comparison • CSV history export for your healthcare provider • On-device skin type analyzer (camera + Vision) • Removal of all advertising

PRIVACY Your skin profile, location, and Health data stay on your device or in your private iCloud. We never sell or share personal data. Ads (free tier only) use Apple's privacy-preserving SKAdNetwork.

DISCLAIMER D3-Sync provides estimates and is not medical advice. Always consult a qualified healthcare professional before changing supplementation, sun exposure, or treatment.

Terms of Use (EULA): https://bigkrzyh.github.io/D3-Sync/terms.html Privacy Policy: https://bigkrzyh.github.io/D3-Sync/privacy.html