Support
Help & contact
Something not working, or a question the answers below don't cover? Email vladp3004@yahoo.com and you'll get a reply from the person who wrote the app.
What's the timer?
Time until the app suggests reapplying. It isn't fixed — it adapts to how long you've been outside and how strong the sun is around you, so it stretches on a grey day indoors and shortens in open sun. If it feels long, that is usually the honest answer: a properly applied film loses only around 30% over a full day. The numbers behind it are on the model page.
What is adaptive mode?
The name for letting the timer use your watch's sensors. It asks for two things: Time in Daylight from Health, and your approximate location. With them, the estimate follows your actual time outside and the local UV. Without them, the app still works — it uses your time zone for the sun's position and assumes you're mostly indoors. You can turn it on from the i button on the home screen.
It says it can't detect daylight time
Health access was skipped or turned off. On your watch, open Settings › Health › Apps › Sunscreen and allow Time in Daylight.
It says it can't detect location
Location access was skipped or turned off. On your watch, open Settings › Privacy & Security › Location Services › Sunscreen. Approximate location is enough.
How often will it ask?
On an ordinary day, once or twice: the morning prompt, and one more if you've had enough sun. Indoors all day, it's just the morning one — the film on its own lasts about fourteen hours, which lands after dark, so the app waits for the next morning. On a day genuinely spent outdoors, a beach or a hike, expect it every hour and a half or so, more than on any other day. That is intentional: those are exactly the days when swimming and sweat take the film off, and the dose is the only way the app can see it.
I'm not getting notifications
Check Settings › Notifications › Sunscreen on your watch and make sure alerts are allowed. Reminders that would land at night are delivered silently, so also check that a Focus mode isn't holding them.
Do I need an iPhone app?
No. Sunscreen runs entirely on the watch.
Does it know my skin type or my SPF?
No, on purpose. Skin type predicts how quickly you burn; this is a photoaging model, which is a different pathway. And the SPF on a bottle is measured at a lab thickness almost nobody matches. The model page explains what's left out and why.
Is this medical advice?
No. The timer is an estimate, modelled from Apple Weather's UV index and cloud cover, the sun's elevation and your Time in Daylight — not a measurement of your skin. Check with your doctor before relying on these timings, and keep following the directions on your sunscreen.
How do I delete my data?
Delete the app. Everything it stores lives on your watch. See the privacy policy.
Bugs and requests
Both welcome, at vladp3004@yahoo.com. For a bug, please include your watch model and watchOS version.