Ning Apps, or third-party applications based on OpenSocial 0.8 is released and serve as new, rich features for 1.5 million+ Ning Networks and 33 million users. Ning Network Creator can now add Ning Apps to expand the functionality of their Ning Network and increase engagement by their members. Most social platforms rely exclusively on members adding applications to their profile pages, but when a Network Creator adds a Ning App, that Ning App is available to all of the members of that Ning Network in a flash. This means that with one action, a Network Creator can make their Ning App available to hundreds, thousands or even millions of people instantaneously.
More info: Ning Apps Directory