I have been investigating the Facebook Open Graph API. There is a \"manage pages\" extended permission which allows publishing to a user\'s Facebook Page news feed/wall via \"im
Yes, the best you can do is direct them to the add.php url. You can't do anything to help them remove the app.
The good news is that the user used to have to go through the add process AND physically decide to "enable" the tab by finding it in the tab dropdown on the page. Facebook has recently changed that and it seems that the tab is now immediately enabled after a user adds the app to their page.
As for "has_added_app" that works... sorta. It will tell you if the app is added to the page, but it won't tell you if the tab is enabled. For example, a user can disable the tab but still technically have the app installed on the page. Therefore "has_added_app" will return true even though the tab isn't actually visible.