If you’re not familiar with Drop.io, Drops are essentially private webpages where users can contribute digital files and also submit content via other methods like phone (MPs) or fax (documents). That content can then be shared through email, embeds, RSS, and other means. With the launch of an API, developers can pick and choose which inputs and outputs they’d like to use in their apps, and then utilize Drop.io for the storage of the files that are created by users of them. One of Drop.io's developers explains this in additional detail in the video below:
To demonstrate, Drop.io has built a number of sample applications, the most obvious of which is uSend.io, essentially a simple clone of YouSendIt. You select a file from your harddrive, select the recipients, and send it out. A drop is created, and the recipients access it via the link sent to their email. Other simple demos include Collab.io for organizing meetings with Drops, and TwitterSlurp, which builds an archive of Tweets about a specific topic as a Drop.