Sun Day turns your phone into a personal sun coach. Get real-time UV for your exact spot, track your vitamin D minute by minute, and get a gentle nudge the moment your skin needs a break. 100% free, no ads, no tracking. iOS & Android.
I'm Antoine, and Sun Day is the app I wish I'd had the summer my girlfriend came back from a "quick 20 minutes at the park" with shoulders the color of a stop sign.
The problem. Weather apps show a UV number next to the temperature, and that's it. No context, no alert, no idea if that "6" means grab a hat or go make vitamin D. Meanwhile ~1 adult in 2 in Northern Europe is vitamin D deficient, and skin cancer rates keep climbing. The data exists, it's just buried.
What Sun Day does. ☀️ Real-time UV for your exact GPS location (powered by Open-Meteo) 🧬 Personalized vitamin D synthesis, adjusts to your skin type, clothing and age 🔔 Smart alerts: "you hit your daily dose, time to cover up", never spam 🌙 Moon phase, sunrise/sunset, hourly forecast as bonus 🔒 Fully on-device. No ads. No tracking. No account.
Why free and ad-free. Sun Day is built by DIH LABS, a French non-profit. We don't need to monetize your attention, dues and our other apps fund the work.
I'd love to hear: what's the one thing a weather app has never told you about the sun that you wish it would? Any feedback on the vitamin D model especially welcome, it's the part I'm most obsessed with getting right.
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About Sun Day on Product Hunt
“Your UV coach - know exactly when to soak it up or hide”
Sun Day was submitted on Product Hunt and earned 0 upvotes and 1 comments, placing #160 on the daily leaderboard. Sun Day turns your phone into a personal sun coach. Get real-time UV for your exact spot, track your vitamin D minute by minute, and get a gentle nudge the moment your skin needs a break. 100% free, no ads, no tracking. iOS & Android.
Sun Day was featured in Android (57.1k followers), iOS (110.2k followers) and Health & Fitness (82.5k followers) on Product Hunt. Together, these topics include over 99.4k products, making this a competitive space to launch in.
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Hey Product Hunt 👋
I'm Antoine, and Sun Day is the app I wish I'd had the summer my girlfriend came back from a "quick 20 minutes at the park" with shoulders the color of a stop sign.
The problem. Weather apps show a UV number next to the temperature, and that's it. No context, no alert, no idea if that "6" means grab a hat or go make vitamin D. Meanwhile ~1 adult in 2 in Northern Europe is vitamin D deficient, and skin cancer rates keep climbing. The data exists, it's just buried.
What Sun Day does.
☀️ Real-time UV for your exact GPS location (powered by Open-Meteo)
🧬 Personalized vitamin D synthesis, adjusts to your skin type, clothing and age
🔔 Smart alerts: "you hit your daily dose, time to cover up", never spam
🌙 Moon phase, sunrise/sunset, hourly forecast as bonus
🔒 Fully on-device. No ads. No tracking. No account.
Why free and ad-free. Sun Day is built by DIH LABS, a French non-profit. We don't need to monetize your attention, dues and our other apps fund the work.
I'd love to hear: what's the one thing a weather app has never told you about the sun that you wish it would? Any feedback on the vitamin D model especially welcome, it's the part I'm most obsessed with getting right.
Thanks for checking it out 🌞