Dropbox pioneered the personal cloud service, where all your stuff would be available no matter what device you were using. On Android, it holds its own—even against the highly integrated Google Drive. Dropbox can also act as a seamless backup for your images, automatically uploading every photo to the cloud. It even includes some light image editing tools. If you're the type of person with lots of files already stored in Dropbox, this app is a must-have. Droid App

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