Manimatana Lee spent the past five years building one of the hottest commodities on the internet: a group of people who reliably watch her videos on TikTok.

She built an audience of nearly 10,000 followers with videos of herself vacuuming her house in Wisconsin while her youngest daughter napped in a carrier on her back. A video of Lee dancing and doing the dishes — while wearing her sleeping baby — has been watched more than 1 million times since November.

Now, with the Supreme Court soon to rule in a case that could determine whether TikTok could be banned in the United States over national security concerns, Lee and other Americans looking for alternatives are downloading Xiaohongshu, a social media app that is popular in China and little known outside the country.

“How funny would it be if they ban TikTok and we all just move over to this Chinese app,” Lee wrote Monday on TikTok, encouraging her followers to join her.

Xiaohongshu was the most downloaded free app in the U.S. Apple store Tuesday. More than 300 million people, mostly in China, use the app, where they share short videos as well as still, text-based posts. People flocking to it said, in interviews and on the app, that they wanted to show they do not share Washington’s concerns about TikTok’s ties to China.

TikTok is owned by the Chinese company ByteDance.

Lawmakers in the United States and other countries have warned that the Chinese government could use TikTok to access data about its users such as location and browsing histories. Officials in Washington say they are also concerned that China could use TikTok to spread false information among the 170 million people who use it in the United States.

The Americans on Xiaohongshu have rallied under the hashtag “TikTokrefugee,” which had been viewed 100 million times and sparked around 2.5 million discussion threads on the app by Tuesday.

Joining the app has put American users in closer contact with people online in China than they have ever been on TikTok, which is not available in China.