The app, owned by a private company based in China, has gained a sizable user base — and its videos are suddenly all over the internet.
On TikTok, the app that is suddenly everywhere on the internet, a certain genre of videos all start the same way: a first-person view of an arm reaching into a refrigerator while the intro to the Village People song "YMCA" plays.
The person behind the camera pulls out some food — an egg or a piece of cheese or even a tortilla — walks it into another room, and, as the song's horn section kicks in, the food is whipped into the face of another person.
The video abruptly ends before showing the reaction of the person, sometimes literally with egg on their face.
The sneak attacks are just one of the many different jokes, pranks, memes and trends that trace their origin back to TikTok. And while the app has become wildly popular in its own right, videos created on its platform are making their way onto other platforms and across the internet.
A YouTube search turns up an almost inexhaustible list of TikTok compilations, and TikTok videos are routinely uploaded to Twitter, where they can amass millions of views.
TikTok, which launched in China as "Douyin" in September 2016, describes itself as a forum to "capture and present the world's creativity, knowledge, and precious life moments, directly from the mobile phone." It is owned by Bytedance, a startup based in China that is considered one of the world's most valuable private companies.
TikTok users tap and hold to record a short video and can add music and visual effects. The videos can then be uploaded with hashtags to join a variety of topics and trends. Its functionality — and the creativity it has fostered — echoes the six-second video-sharing app Vine, which shut down in 2017.
Most of the videos, which tend to last around 15 seconds, show someone dancing, lip-syncing to a song or video clip, or pulling some kind of running gag (see the above egg example), but the app has also gained followings among some particular groups, most notably military personnel.
Adam Blacker, vice president of mobile research and communications at the mobile analytics firm Apptopia, said TikTok has grown fast, noting that it added 30 million usersin one three-month stretch of 2018.
"People talk about the numbers with TikTok because they're impressive, but what's more interesting is its growth comes at a time when stalwart American social media apps have stagnated user growth," Blacker wrote in an email. "Not only that, but TiKTok is an app created in China that is having success in the United States. Outside of games, this is essentially unheard of."
Blacker said Apptopia estimates TikTok had 251.2 million monthly active users as of December, which counts people across three apps: the U.S. version, a version popular in Asia, and a separate app only available in China.
The app's users skew young, with Apptopia finding that people 11 to 20 make up its biggest contingent, at 35 percent of all users, with 21- to 30-year-olds the next biggest, at 23 percent.
TikTok declined to comment on user data.
The U.S. version of TikTok was formerly known as Muscal.lybefore ByteDance acquired it in 2017 and rebranded it. The company has also worked to attract users in international markets,launching "lite" versions of its app in India and Indonesia, where wireless internet access isn't as ubiquitous.
Other companies have taken notice of TikTok's success. In November, Facebook launched a nearly identical app called Lasso.
Part of the charm and attraction of TikTok is that its younger users have embraced it as a place to experiment with the kind of internet humor that hasn't thrived on other platforms.
"In a world where everyone's content inevitably begins to look the same, TikTok videos feel bizarre and new," wrote The Atlantic's Taylor Lorenz. "It's an app full of people posting strange content to the internet with zero self-awareness or shame."
Others have noted that the app offers a respite from other platforms that have become associated with abuse and hate speech. Kevin Roose in The New York Times called the app "a refreshing outlier in the social media universe" that brought him the rare sensation of "happiness."