Best Automatic Vitamin D App
The world's first automatic vitamin D app that tracks your sun exposure and vitamin D synthesis completely hands-free. No manual logging, no thinking required. Just automatic tracking that works.
Why Rays is the Best Automatic Vitamin D App
If you want the best automatic vitamin D app that truly works in the background without any effort, Rays is the only choice. It's the world's first automatic vitamin D tracking app, and still the only one that's truly automatic.
The World's First Truly Automatic Vitamin D App
Rays is the best automatic vitamin D app because it's the only app that automatically detects when you're outdoors and tracks your vitamin D synthesis in the background, completely hands-free. No manual logging, no timers to start, no buttons to press. While other apps claim to be 'automatic' but still require you to start sessions, Rays works silently in the background, learning your patterns and getting smarter over time. It's the difference between automation and true automation.
Background Operation That Actually Works
Rays runs efficiently in the background without impacting battery life or requiring any action from you. iOS monitors your location and steps every few minutes when the app is closed, and detection happens within seconds when open. The system automatically filters out vehicle travel (since you don't synthesize vitamin D while driving) and uses gap-filling technology to recover missed outdoor time during stationary periods. No thinking required, no effort needed. Just automatic vitamin D tracking that works.
Intelligent Detection with 80-85% Accuracy
Our advanced outdoor detection system combines GPS accuracy analysis, movement pattern recognition, step analysis with treadmill detection, location context understanding, and light sensor data (when available) to achieve 80-85% detection accuracy. The system learns your outdoor patterns at frequently visited locations and times of day, improving accuracy over time. It's not just automatic. It's intelligently automatic.
Personalized Automation That Adapts to You
Rays doesn't just track automatically. It personalizes automatically. Our machine learning adapts to your unique routines, frequently visited locations, and lifestyle patterns. The system learns when you're typically outdoors, where you spend time, and how your schedule works, then adjusts its detection and recommendations accordingly. You get automation that's tailored to your life, not a one-size-fits-all solution.
Privacy-Protected Automation You Can Trust
Rays uses geohash clustering technology for weather data (clustered to approximately 5km radius) to protect your exact coordinates, while precise location is used only for accurate outdoor detection. All processing happens on your device when possible, and you maintain complete control through standard iOS/Android location permissions. You can review and delete your location data at any time. Automatic tracking doesn't mean sacrificing privacy.