Описание тега yii-extensions
Custom third party extensions/reusable components for the Yii framework, which provide common and repeatedly used functionalities for web applications. Use this tag only for such 3rd party extensions, not built-in components like Zii widgets.
Yii - extensions are custom reusable components for the Yii framework, which can be reused easily to implement commonly required web application functionality.
More information can be seen in the Extensions section of the definitive guide.
Available (published) extensions are expected to be listed in the official website here.