This is definitely a cool trick, but the real problem with FB app privacy is that unless you completely disable the app platform on your account, any apps that your friends install can also see information about you.
Does it really matter how much you can limit your own apps, if anyone on your friends list can install any app and silently give away your information to some unknown third party without your knowledge or consent?
Not true. Just go to the Apps, Games and Websites section of the Privacy Settings and use the "How people bring your info to apps they use" section to select exactly what you want apps your friends use to be able to access about you. Doesn't require completely disabling the app platform.
Does it really matter how much you can limit your own apps, if anyone on your friends list can install any app and silently give away your information to some unknown third party without your knowledge or consent?