Secret, an app that lets users share anonymous confessions with others, is no more.

In a piece posted on Medium Wednesday, Secret cofounder David Byttow said that after less than a year and a half of availability, the app would be shuttered and money returned to investors; the reason, he said, is that Secret “does not represent the vision” he had when starting it. The app, which had been free to Android and iOS users, is no longer available through the app stores for either mobile platform.

In his post, Byttow said that while he believes in anonymity to promote “honest, open communication and creative expression,” it’s “the ultimate double-edged sword, which must be wielded with great respect and care.” That sounds pretty vague, but he also said he intends to post more about what happened to illuminate “the unique mistakes and challenges” the Secret team dealt with.

It was clear Secret had issues for some time. After an initial explosion of popularity, the app fell off the radar screen for many. In January, after a redesign made in hopes of helping the app gain more users, cofounder Chrys Bader left.

I wrote about Secret and one of its competitors, Whisper, in September (see “Confessional in the Palm of Your Hand”); at the time, I enjoyed using both to post, read, and respond to comments. I even arranged an anonymous meetup at a bar through Secret. Only one person showed up, but it was fun anyway because it turned out that my companion and I had a lot in common (we both grew up in the Bay Area, went to UC Berkeley, and majored in English, for instance). Though there was some bullying evident on both Whisper and Secret, I didn’t find it to be much of a problem; the fun of it outweighed the negativity.

And yet, Secret flopped while Whisper is still going strong. Also on Wednesday, Whisper reportedly hired its first president and noted that it has 10 million active monthly users.

So why did Secret, which started out so strong, eventually flop? Maybe it had something to do with how they work. While both let you post and comment anonymously, Secret showed users posts from people they were connected to socially (pulled from phone contacts and Facebook), while Whisper is more truly anonymous in what it shows you. Maybe it didn’t appeal to a big enough group of people. Or maybe users just got bored with it, which could be problematic for Whisper at some point, too.