You can be 100 percent certain that each and every app that says "See who views your profile!" or "stalker tracker " or anything else like that is virus-laden junk.
Facebook may be tracking many aspects of your usage for their own benefit Best case scenario, you'll find out who of your friends installed the same app as.
Why can't I see who is stalking my Facebook profile? There are other social networks that do let you see who's viewed your profile, mainly. How to see who viewed your facebook profile