When you block an app, it won't be able to access any information about you from Facebook or send you any requests.
To block an app from your settings:
Click in the top right corner of any Facebook page and select . Click in the left column. Look for the header and enter the app name. You can unblock them by clicking to the right of their name.
If you received a request for an app and you want to block the app:
Go to the App Center. Click next to the request. Click the link > .
The app may have stored info from when you used it. You can contact the app directly to ask that they delete any info it may still have.
When you choose to unsubscribe from emails from an app, the developers have ten days to update their databases and stop emailing you. If it's been more than ten days and they still haven't stopped, you should report them to the Federal Trade Commission for violating CAN-SPAM.