Who does not want to know which Facebook Apps are in use by friends or even the own partner? Facebook makes it possible to retrieve this information quickly and easily.
Goto link above and replace the appid with the app you want to check
Where do I get the ID from?
You can simply get the ID from the Facebook page of the App or the corresponding company. After browsing to the page of the App, you can see the ID in the link visible in your browser (URL). The ID can be found behind “app_id” or “client_id”. Simply copy this number from the link and add it to the link shown above to see the apps of your friends.