About UV Tracker

Who makes this

UV Tracker is built independently by Trung Hieu Lam, a software developer. There is no company behind it — just one person maintaining the app and this site. For questions or corrections, use the support page.

Why it exists

Sun safety information shouldn't be locked behind a subscription, and a UV reading that only reflects a regional forecast isn't very useful standing under your own patch of sky. UV Tracker is free forever, with no paid tier, because the two problems it solves — "what's the UV here, right now" and "how long can my skin actually take it" — are worth solving for everyone.

How the app estimates

The app combines a public UV forecast with two on-device readings. A camera scan of the sky adjusts the regional forecast for the cloud cover actually overhead, rather than relying on the forecast alone. A single photo of your inner forearm estimates your skin's sun sensitivity, so the safe-sun-time figure is tuned to you rather than a notional average person. Both readings happen on your device and are never uploaded — see how the app measures for the detail, and the privacy policy for what stays local.

What this site is not

UV Tracker is not a medical device and does not provide medical advice, diagnosis, or treatment. Its readings are estimates for everyday sun decisions, not a substitute for a dermatologist. If you have concerns about your skin, see a doctor.