SunDose
For iPhone
UV Index App for iPhone
SunDose is built natively for iOS: live UV from Apple Weather, a session timer on your Lock Screen, and widgets that put today’s index one glance away.
The short answer
SunDose is an iPhone UV index and sun exposure tracking application developed by Fios Apps. It draws UV data from Apple WeatherKit — the same source behind the built-in Weather app — and adds Lock Screen Live Activities, Home Screen widgets and a personalised exposure timer. Free to download, iPhone-only, with your skin profile stored on device.
Built on Apple Weather data
SunDose reads UV from Apple WeatherKit, which supplies “10-day hourly forecasts for temperature, precipitation, wind, UV Index, and more”. That is the same underlying source your built-in Weather app uses, so this is not a claim about having a better number.
What differs is what happens next. The Weather app reports the index; SunDose applies your skin type, your SPF and your sensitivities to it and produces a session length.
Lock Screen Live Activities
A running session appears as a Live Activity, so you can check the countdown, pause or stop it without unlocking your phone or finding the app. On models with the Dynamic Island it surfaces there too.
This matters more than it sounds. A timer you have to unlock, find and open is a timer people stop using by the second afternoon.
Home Screen widgets
Widgets put the live UV index, your hydration progress, your day streak and a one-tap session start directly on the Home Screen, in multiple sizes.
The point is to remove the deliberate act of checking. If the number is already in front of you when you unlock your phone, you make a better decision without having decided to look.
Privacy on device
Your skin profile and your logged sessions stay on your device. The app does not sell profiles or track you across apps — you can read the specifics in our privacy policy.
Location is used to fetch UV and weather data for where you actually are, which is the whole basis of a local UV reading.
Frequently asked questions
- Does the iPhone have a built-in UV index?
- Yes. The built-in Weather app shows a UV Index figure and hourly forecast from Apple WeatherKit. It tells you what the UV is; it does not turn that into an exposure plan for your skin type, your SPF or your medication.
- Which iPhones does SunDose support?
- SunDose is an iPhone app using Live Activities and Home Screen widgets, both of which need a reasonably recent version of iOS. Check the App Store listing for the current compatibility requirements for your specific device.
- Is there an Android version of SunDose?
- Not currently. SunDose is built natively for iPhone, which is what makes the Lock Screen Live Activity and widget behaviour possible in the form described here.
- Does SunDose work offline?
- The UV index and hourly forecast need a connection to fetch current data for your location. The session timer, your skin profile and your logged sessions live on the device and continue to work.
Read more
Sources
- AppleWeatherKit developer documentation
- World Health OrganizationRadiation: The ultraviolet (UV) index
- US Environmental Protection AgencyLearn About the UV Index