The Sample app is a learning example for developers. It is not a tool for editors but rather a showcase for common app functionality at development level. It shows you how to expose actions to the user as user interface elements (buttons) and how to trigger actions. As a developer you should examine the Sample app source code and read the comments in the code.
The Sample app is installed by the
sample-app module. The Dev app group that this app belongs to is only available to the
superuser role. This is configured in the app launcher layout. The app is configured at Configuration >