No it doesn't work. An app only has access to the same information that you have access to yourself. For example, there are apps which claim to be able to tell you who has defriended you. They can do that by periodically checking your list of friends and comparing the list to the previous day (in the same way that you could do yourself if you could be bothered). So those apps do work (but not retrospectively). But if you can't tell who is looking at your profile, neither can an app. It can only guess/lie.