Jack Dorsey Launches Sun Day App to Track Sun Exposure
Block CEO and Twitter co-founder Jack Dorsey has introduced Sun Day, a new app designed to estimate users’ sun exposure and vitamin D synthesis. The app employs a scientifically validated model that factors in UV exposure, location, age, clothing type, and skin tone to provide personalized insights.
How Sun Day Works
Available in beta via Apple’s TestFlight, Sun Day requires users to manually log their sun exposure sessions. By simply tapping a button when entering and exiting sunlight, the app collects data alongside information from the Apple Health app to generate accurate estimates.
Key Features
- Calculates vitamin D synthesis from UV exposure
- Tracks real-time UV index based on location
- Personalizes estimates using demographic and lifestyle factors
- Integrates seamlessly with Apple Health data
Future Enhancements
According to its GitHub white paper, Sun Day plans to introduce more precise calculations incorporating height, weight, seasonal variations, and actual vitamin D blood test results. These updates will further refine the app’s accuracy and usefulness.
Dorsey’s Recent Tech Ventures
This launch follows Dorsey’s recent release of Bitchat, a decentralized Bluetooth messaging platform. Both projects were developed using Block’s AI assistant Goose, reflecting Dorsey’s hands-on approach to exploring new technologies.
