Unsurprisingly, and as usual, this is another Facebook scam. If you’re a retarded moron that actually believes ANY app can tell you who has viewed your profile, allow me to tell you absolutely categorically that this is impossible. Even with an API access token with full privileges to your account, no such information exists that an application could query.
It draws you in, because you’re stupid, and think that just because an application advertises a ‘feature’, it must be true. It’s not true. This claim is never true. If you actually install this piece of shit, it just spams the same link to all of your friends, and tries to get you to fill in dodgy surveys in order to ‘unlock’ the real information. The real information doesn’t exist. Even if it does give you a list of ‘friends’ who have allegedly seen your profile, the information is forged. Meanwhile you’ve spammed your entire account, probably managed to get your computer infected with some kind of malware, and reaffirmed to the rest of the world that you shouldn’t be trusted with a computer.
To reiterate: It’s fake. It’s always been fake. It’ll always be fake.