We've all been there: A distant relative or forgotten acquaintance posts something insulting, vulgar, or just downright obnoxious on Facebook; so, without thinking, you just delete them from your "Friends" list. But what if someone had the same idea about you? Would you even notice if they got rid of you? Well, a Google Chrome extension called Who Deleted Me will tell you who has unfriended you on Facebook.

Who Deleted Me is pretty simple: After you download it, you upload your Friends list to the program, where it will log the number of people you're friends with. From there, it will recheck your list whenever you click on the app and let you know if there have been any changes. The program will also scan your list periodically on its own to notify you if anyone has dropped you. Who Deleted Me differentiates between people who outright unfriended you and those who simply disabled their Facebook accounts.

If you have been unfriended, know that you're not alone. In his research on the subject, Christopher Sibona—a PhD student at the University of Colorado Denver when he released his study—found that, "The most common type of friend who is unfriended is the high school friend (18.6 percent), followed by other (uncategorized), friend of a friend, and work friend."

"High school friends are unfriended for making online posts that are polarizing and for posting too frequently about unimportant topics," Sibona concluded. "Work-related friends are commonly unfriended for engaging in disliked offline behavior and are not typically unfriended for their posting behavior." Sibona's study on Facebook behavior also revealed that the person who originally sent the friend request is more likely the one to be deleted.

There has been an uptick in similar apps in recent years, including Who Unfriended Me?, which is available on Google Play, and a rival service on the App Store. You can also download like-minded services to track your Twitter followers.

Remember, though, none of these programs are approved by either Facebook, Twitter, or whatever social media platform you're monitoring. In fact, Facebook urges people to stay away from any add-on that doesn't go through their Application Programming Interface, or API. If a program doesn't use Facebook's API, that means it's not adhering to the company's privacy policy or its terms of service agreement. So be careful, and maybe cut down on all of the political posts and photos of your dinner if you want to avoid deletion.