This plugin is supposed to be a working example of a RESTful webservice implementing authentication by OAuth.
The API is located at installation_url/plugins.php/restipplugin/api for now.
Full german API documentation is available here.
Root administrators can manage which external apps are allowed to access the api on a new page located in /admin/config.
Applications can be created, updated and deleted there. It is also possible to activate/deactivate a certain app. Access keys are managed here too.
Users can manage which external apps are allowed to access their data on a new page located in /settings/config.