Everything you need to know about Dropbox, the most popular, most integrated third-party cloud storage and sync solution for iPhone, iPad, and Mac
Dropbox is a cloud storage and sync service that, on the Mac, can make sure anything in its special folder is kept safe online and mirrored on any other Mac you install it on. On iOS, the Dropbox app gives you near-line access to all the same files. What's more, Dropbox provides a powerful API for developers that allow many other apps to tie into their service and use them for cloud storage and sync as well. The apps are free, as is a small amount of storage. More is available for a price.