Every application in the App Store gets single sign-on configured automatically at install time by default, including applications that have no login system of their own. You never set up an identity integration app by app - it's part of what "installed" means on VCloud. An install can opt out of this in favor of a local account instead, for the rare case where that's genuinely what's needed, but it isn't the default.
This is a meaningful departure from configuring sign-on yourself. On a self-managed stack, wiring up single sign-on for each application individually is real, recurring work, and it's routinely the thing that gets skipped under time pressure - leaving one app behind on a separate password while everything else is unified. On VCloud there's nothing to skip: it's applied the same way, every time, for every app.
Your own identity provider, not just Google or GitLab#
Sign-in isn't limited to the Google or GitLab account you started with. Your organization can connect its own enterprise identity provider - Microsoft Entra ID, Okta, Google Workspace, Active Directory, Auth0, and several others directly, or any SAML, OpenID, or LDAP provider generically - through a self-service setup wizard. See Integrations › Identity providers.
See Concepts › Single sign-on for how your organization's identity provider choice flows through to this, and Deployments for where in the install process it happens.