Earlier this year I mentioned a handy wrapper for easier use of the free OpenWeatherMap API.
Here’s a beautiful example app called Sol for displaying weather from Comyar Zaheri.
Sol demonstrates how to gather weather information from the Wunderground Weather API, and demonstrates how to create a great looking interface using Core Graphics for each different weather type.
You can find Sol on Github here.
You’ll can get a key for the Wunderground API here.
A nice weather example app.