WordPress.org

force-frame is a WordPress plugin that allows you to force your WordPress website inside an iframe in another website, with cross-domain support.

Features

• Redirect to parent site: when users access your website directly, they will be redirected to the parent site where your site is shown in an iframe.
• Inject site's URL into parent site's URL: when users navigate between pages in your site, the URL they navigate to is injected in the parent site's URL using the fragment or a GET parameter; if the parent site's URL is then shared, the iframe will load the correct page of your site
• Cross-domain support: it will work even if your site and the parent site are on different domains

Links: Author's Site