Jack Dorsey Launches ‘Sun Day’ App to Track Sun Exposure and Vitamin D Intake

Jack Dorsey has unveiled a new wellness-focused app called Sun Day, designed to help users monitor their sun exposure and vitamin D intake.

Following the recent launch of Bitchat, an offline messaging app, Sun Day continues Dorsey’s foray into innovative digital tools that promote health and connectivity beyond traditional internet use.

Sun Day utilizes a phone’s location to gather real-time data on the local UV index, allowing users to manually track their time in the sun. The app then estimates vitamin D production based on individual factors such as skin type, clothing, and time of day.

In addition to tracking sunlight exposure, the app offers detailed environmental insights, including sunrise and sunset times, cloud coverage, and personalized burn limits tailored to current UV conditions.

With growing awareness around vitamin D deficiency and safe sun practices, Sun Day aims to offer users a more mindful way to manage their time outdoors.