Weathercube is an interesting and graphically pleasing approach to giving you the weather on your iPhone or iPod touch. It is not universal, but will run on an iPad in 2x mode. It sells for US $1.99.
Weathercube supports several gestures which will get you to extended forecasts, other pre-set cities, and even the settings. It provides a lot of information, and swiping the screen gets you a slick animation that looks like the cube is turning in perspective. If you look at the app icon you can get an idea of the animation effect.
Gallery: Weathercube for iOS
