A recent project of mine has been ContribKanban.com for the Drupal community. The name speaks for itself - it provides a way for contributors to work on Drupal.org project issues queues through a kanban board. This app has two purposes: visualize the Drupal.org project issue queues in a useful fashion, and provide an experiment that tries to fully utilize Drupal.org APIs.
Facebook Album 2.0 Coming soon! mglaman Tue, 06/25/2013 - 18:44
I've been hard at work in the labs revamping the Facebook Album plugin for WordPress. Very soon you will be able to use a Facebook application to authenticate with the Facebook API.
Google+ has released a rough outline on their API for accessing data. The Google+ API only allows for read-access to data, but this will still allow you to integrate a visitors social features around Google+.