Dropbox class
Dropbox is the easiest way to store, sync, and, share files online. There's no complicated interface to learn. Dropbox works seamlessly with your operating system and automatically makes sure your files are up-to-date.
About
PHP Dropbox is a (wrapper)class to communicate with Dropbox.
Documentation
The class is well documented inline. If you use a decent IDE you'll see that each method is documented with PHPDoc.