Dropbox is the official app for the service of the same name. With it, you can access all the files in your Dropbox account, and sync them with your android device.
From the Dropbox app you can download files from your account, upload images immediately after taking a photo, share links to your content through a variety of platforms (message, Twitter, Facebook, etc) manage your account's files, and much more.
The Dropbox app can also sync all your photos and videos automatically. Enable this great feature, and anytime you take a photo or video, it's not only saved to your device but automatically uploaded to your dropbox account.
This Android version of Dropbox is essential for any user of this king of cloud storage services. With it on your android device, you'll not only be able to save your most precious documents in the event of a hardware failure, but also basically have a hard drive in the cloud to use as you wish.