Whtr is a free universal app (with in-app purchase options) with a fresh take on how weather information should be presented and organized.
The screens are very clean and simple. The app UI is gesture-based, so swiping up brings up the next screen. There is a clever option to drag the current temperature around an arc that represents a clock to show you future temperature predictions. You can also use the same gestures for predictions of air quality.
The free version is quite complete, providing wind speeds, conditions in my favorite cities, sunset and sunrise times, dew point and more. The app covers about a million locations around the world, and using my iPhone's GPS capabilities it had no trouble pinpointing my home location.
There are 2 in-app purchases. The $1.99 purchase adds more features, including adding more than two cities as favorites and providing visibility readouts. An HD Radar upgrade ($2.99) provides a NOAA-sourced radar plot.