This app is for entertainment purposes only
This list is generated and retrieved from Facebook based on the following code:
Any activity you do on Facebook like messaging someone, liking a post ,commenting on a status .... is triggering something in the code that changes the order of this list, noting that some of these factors have a higher priority than others.
If you are interested in knowing who's viewing your profile you have to interpret this list and look for people who you haven't interacted with recently (Including those you've visited their profile) as well as those that are moving towards the top of the list, those will be the ones visiting your profile and viewing your photos.
People appearing on the top of the list are the ones with the most interaction going on between your profile and their's, however viewers might be in any place in the list, i.e: the top one might be there because you are chatting with him/her a lot but the 13th is there because he/she has checked your profile once. (Chatting has a higher priority that viewing once but multiple views has a higher priority that a single message).
Also be reminded that the list reflects what's going on, on your profile, i.e. if there are no new activities on your profile the list will stay the same until something new happens.
Hint: For those of you who are concerned about their privacy kindly note that the login page is provided and secured by Facebook just like any other app that is integrated with Facebook and for those of you doubting that the app works as described, look into the app when you change your profile photo or add a new album, and test the app yourself.