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.
Configuration
The Sample app is installed by the sample-app module. This app is only available to the superuser role by default. Permissions are configured here: /modules/ui-admincentral/config/appLauncherLayout/groups/dev/permissions/roles
The app is configured at Configuration > /modules/samples-app/apps/sample.
Overview
Content Tools