A 3rd Party API Showcase for Your API
I stumbled across the Twitter Counter API in my monitoring for the API Stack this morning. The Twitter Counter API allows you to retrieve key metrics on any Twitter account like username, url and avatar. All data you can get via the Twitter API, but with Twitter Counter API you get additional information like account growth statistics and ranking, that Twitter doesn't provide at all.
I find it fascinating that someone can build an API to augment an existing API, which is why I keep talking about it, I guess :) We are seeing a more standardized version of this with API aggregation providers like Singly and Adigami, where they not only aggregate APIs from a variety of sources, they also build entirely new APIs based the added value that is created after they are brought together.
Thinking about if further, it would be cool if you could submit your API to be listed in your parent API providers API area. Think of APIhub and Mashape, but every API area would have its own 3rd API marketplace. API providers often allow 3rd party developers to submit code libraries and samples to be listed as resources, as well as applications for listing in an application showcase. So it makes sense to potetially allow for your developers to submit APIs for validation and publishing into a designated area.