There are lots of ways to pay for things with your phone. But Venmo has a smart mixture of clean design, ease of use, and social functions that give it an edge. It doesn't do much, but it does let you easily send and receive payments from friends. And unlike other payment systems, it has momentum. It's usually the app people ask about when the group is splitting up the check.

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