At its core, Dropbox is a place in the cloud where you drop stuff. That stuff can be pretty much anything from music to photos to documents. It’s a great way to keep files that you may want available for your mobile devices, and for files that you may want to share. Dropbox includes apps for most computers and mobile devices including Windows, Macintosh, some Linux distributions, iOS, Android, BlackBerry and Kindle Fire. There is a third-party app for Windows Phone.