There is no shortage of weather apps in the App Store but Ultraweather takes a slightly different approach. While it isn't as robust of a choice as some others, it has a great interface made possible by local Instagram users in your area.
Instead of stock backgrounds, you'll be able to upload your own or view photos others have taken in your area.
Ultraweather doesn't contain a plethora of weather related information but gives the information that a bulk of users care about such as high and low temps, wind speeds, chance of rain, and a weekly extended forecast.
Similar to how Yahoo Weather uses Flickr images in your local area, Ultraweather uses Instagram photos. If there aren't any photos available in your local area, you can also upload your own and use them as your background.
If anything, it's a neat concept. It'd be nice to be able to see who is uploading the photos in order to find more local followers in Instagram though.