Yahoo! aren't really well known in the apps department. Sure they have some apps for their services but they're all pretty average. However they've just stepped up their game a little with a new standalone weather app.
If you didn't know already, the stock weather app that comes with iOS is powered by Yahoo! data.
This new standalone app is actually one of the prettiest weather apps I've seen on iOS. When you first launch it you're given your location at the top, the temperature and a photo as the background. The photos used in the background are directly from Flickr. Usually they'll be pictures from around your area. But from the pictures I found, they were hundreds of miles away. If you're in a city you might have better luck.
You can swipe up to reveal the weather for the next few days. As you swipe up the background blurs out, pretty neat animation. You can swipe up further to reveal more detail about the weather. It'll even include sunrise/sunset, wind speed and pressure. All are shown in very nice animations.
Like most apps, this one seems to be limited to iOS only. No Android version in sight.