As described -here- I wanted to restrict an app so that it's accessible from just one country using the following tag, but it's not working, I can access the App from Switzerland (CH). Any idea what the problem could be?
<meta property="og:restrictions:country:allowed" content="DE" />
The object level restrictions apply to Open Graph content, not applications. I presume you were trying to add the meta tag to html content in the app.
From a bug filed on facebook: https://developers.facebook.com/x/bugs/343431899129688/