Whisper describes itself as "a mobile social network where you can anonymously share your inner-most thoughts on all topics family, love, sex and sexuality, drugs, coming of age, dreams, joy and spirituality".
After choosing a photo that can be enhanced using filters, users write a text displayed over the photo and share it with other users who can comment anonymously on the post.
"I secretly hate football. I don't get it. I've been faking it this whole time. I'm a guy," one user wrote.
Some of the posts are humourous, while others are more serious in tone and address subjects such as sexual fantasies, depression and suicide, as well as stories of sexual abuse.
The crude nature of some of the posts prompted law enforcement officials in Kilgore, Texas, to post a notice on Facebook warning parents about the potential dangers of the application.
"Content is posted anonymously and therein lays the problem with the app," the Kilgore police department wrote on its Facebook page.
"With anonymous posts come bullying, harassment and inappropriate content being posted."
Caroline Conley, a psychotherapist based in Washington, D.C., who works with young people, said the anonymous nature of the site is disturbing.
Suicide is the second-leading cause of death among college students, Conley noted.
"Anonymity is a double-edged sword. While it empowers people, giving them the confidence to express their feelings, it would be horrible and tragic if bullying or encouragement of negative behavior led to suicide."
Whisper has employees at several college campuses, including the University of Texas, who are responsible for promoting the app, monitoring the feed and deleting inappropriate content, according to the company.
But some students have expressed concern over the amount of secrets posted in an apparent cry for help that fail to receive productive responses.
"One of the problems is that it's difficult to know how to offer assistance to someone calling for help on an anonymous social media platform," Patrick St. Pierre wrote in the Daily Texan, the university's student newspaper.
Whisper's developers have now attempted to fill that void with a new mental health resource called Your Voice.
"By now you've probably seen Whisper users talk about issues that can sometimes be deeply troubling in their lives, things you would never want to post on your usual social network," Whisper's developers wrote in a blog post.
"Your Voice wants to help those people and locate resources they may need."