On the left side bar beneath projects, you can click on “apps”
Here you have an overview for all the apps you can download or activate. Apps with a key symbol in the corner have to be activated with an license key. Other apps can just be installed and others are already installed.
Apps with a green headline are already installed, blue line are installed and activated and yellow line are not installed yet.
For more information regarding an app, click on it.
In this description you can read about the app and see details like download size.