Closed Platform
Also known as a walled garden or closed ecosystem, a closed platform is a software system where the vendor has exclusive control over applications or content that is available within that platform.
(en.wikipedia.org) Closed platform - Wikipedia website
ROAM_REFS: https://en.wikipedia.org/wiki/Closed_platform
A closed platform, walled garden, or closed ecosystem is a software system wherein the carrier or service provider has control over applications, content, and/or media, and restricts convenient access to non-approved applicants or content. This is in contrast to an open platform, wherein consumers generally have unrestricted access to applications and content.