TikTok, a new app that allows users to create and post short videos set to music, has become a smash hit in the United States as it rapidly approaches 80 million downloads.

According to research firm Sensor Tower, TikTok had more than 6 million global downloads in October alone, propelling the app to the top of the free category in the Apple App Store.

Free iPhone Category Rank in App Store via Sensor Tower

TikTok gained further mainstream attention when Jimmy Fallon added it to The Tonight Show’s challenge series, where the celebrity host asks viewers to submit videos on TikTok showing themselves doing various comical tasks, such as rolling around like a tumbleweed.

According to ByteDance, the Chinese internet giant that owns TikTok, the first competition generated more than 8,000 submissions and 10.4 million engagements, marking the biggest spike TikTok has seen from a single challenge.

“We’re looking for things that really engage people, and TikTok is a place where you can let your creativity shine,” said Julie Harrison-Harney, director of digital at The Tonight Show. “It has that short-form, mobile energy.”

Given this high-growth, incumbent social networks giants have begun to take notices. So much so that Facebook has launched a standalone TikTok-like app called Lasso. However, there are questions surrounding Lasso’s viability as Sensor Tower estimates it has been downloaded fewer than 10,000 times across both iOS and Android.

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Despite this recent success, the fleeting nature of the app market makes it difficult to gauge whether TikTok is the next long-lasting social app or nothing more than a short-term trend.

More: TikTok is the latest app to skyrocket in popularity. Here’s why it might have staying power
Related: Facebook quietly launches a TikTok competitor app called Lasso