Just run a test form facebooks Open Graph Object Debugger:
https://developers.facebook.com/tools/debug/og/object/
Warnings That Should Be Fixed: Share App ID Missing.
The 'fb:app_id' property should be explicitly provided, Specify the app ID so that stories shared to Facebook will be properly attributed to the app. Alternatively, app_id can be set in url when open the share dialog.
Maybe you should consider a form field in your plugin, so it is possible to enter a Share App ID from facebook.
Thanks for a nice plugin