In JoomShaper Quickstart (Demo content) we used both Joomla! core and additional extensions. Here is a full list of them:

• SP Page Builder Pro - Pro version is built-in within QuickStart only (JoomShaper.com)
• AcyMailing Starter (component + module from Acyba.com)
• Joomla Content Component (Joomla core module)
• Breadcrumbs (Joomla core module)
• Custom HTML (Joomla core module)
• Search (Joomla core module)
• Menu (Joomla core module) 

Where do you get extensions from?

Apart from the few dozen extensions that are part of the quickstart installation (developed by Joomla and the JoomShaper team), you can find thousands of additional extensions developed by third parties on the web. Most of these are listed on extensions.joomla.org, the Joomla Extensions Directory (or JED, as it is fondly called by the Joomla community). Anytime you can install additional modules, plugins, or components. But remember the main rule: less is more, also in the security area.