If you know what BeReal is, you’re either a French teen or a U.S. college student, or you found out about it 10 minutes ago.

The social media site—now the 28th most downloaded free app in the App Store—was founded by two French entrepreneurs in 2020, leaped to popularity in Europe last summer and has been catching fire on college campuses since the fall. But after a critical mass of campus newspapers began reporting on the social app du jour this spring, all of a sudden, in a Wordle-like combustion, BeReal blew up.

The premise of the app is as simple as the description on its TikTok page: “No filters, No followers, No ads, No bullshit.” Once a day the entire BeReal network (estimated at 2.5 million daily active users, according to Apptopia) simultaneously receives a push notification, telling them it’s “Time to BeReal.” Users are then prompted to take a photo within the next two minutes and share it with their circle. The post includes two images from the phone’s front- and back-facing cameras. It doesn’t allow any editing or fancy filters. If you miss the two-minute window, you can still post later, but your shots are marked with a stamp—a modern-day scarlet letter—indicating their tardiness. Critically, users can only see their friends’ photos if they themselves post.

The intended result is unfiltered social media, a strike against highly curated Instagram feeds and effortful, effect-filled TikTok videos. Whether BeReal will maintain its momentum is to be determined. It could become the next Snapchat or it could fizzle out, like Poparazzi, Dispo and Yik Yak before it. To understand its rapid rise, we’ve assembled a timeline: 18 months in the life of an out-of-nowhere social media phenomenon.