Sunz
Sunz turns sun exposure from guesswork into a plan. The app reads the real-time UV index for your location, crosses it with your skin phototype, and gives you a concrete exposure window — when to go out, how long to stay, and when you're done for the day — so tanning is progressive instead of a day-one burn. Built French-first as a commission for the same consumer-app studio behind GoPilates and TryIt, and shipped to the App Store as a native SwiftUI build.
What Wasn't Working
Tanning is guesswork: people either burn on day one or give up. Safe exposure depends on the live UV index and your skin type — numbers nobody calculates by hand on the beach.
How I Fixed It
Read the real-time UV index, cross it with the user's declared skin phototype, and turn it into a plan: a personalised exposure window with clear stop signals, updated as conditions change.