How to block Facebook apps?

[TheRandomGuy7]

I have used this 21 questions app ONCE on Facebook and pressed the allow access to profile button thing. Now I looked at my wall and it is spammed with random bull**** from the app! So how do I sorta 'unallow' the app, block it and maybe delete it? (If you can)

[Friendlyclub556]

To delete an application on Facebook, log in into your account; 1. Go to Privacy Settings page from the "Account" drop-down menu. 2. Click the "Edit your settings" link under the applications. 3. Click on the application you'd like to remove.