iOS: Weather apps aren't exactly an unusual category, but the SunSmart app has a couple of features to recommend it. It's backed by Cancer Council Victoria, and it offers advice on what the UV levels are expected to be in your location.
The app can also be configured to offer reminders about using sunscreen and what times of day sun exposure is less risky. Skin cancer is the most common cancer in Australia, so taking sensible measures is a summer essential.
SunSmart is a free download for iOS devices.