CloudCal offers one of the most unique ways of showing you how busy you are on any given day. The Android exclusive uses a system it calls Magic Circles, which turns the days of the month into clock faces and shows different colored circles, or segments of a circle. We also like that you can attach photos, audio files, and Dropbox files to specific events.
Weather Underground combines a slick design with a focus on really useful weather information. We particularly like the ability to report weather conditions in your area and the extremely useful comparative forecasts that deftly show how conditions have changed since yesterday. With an accompanying set of useful widgets, it's the best weather app on Android. Droid App