Musical.ly Inc., the maker of a social-media app popular among teens and tweens, has agreed to be acquired by Chinese news and information site Beijing Bytedance Technology Co. for as much as $1 billion, according to people familiar with the matter.

The deal comes three years after Musical.ly’s 30-something co-CEOs Alex Zhu and Luyu Yang launched the social-media app to capture the YouTube phenomenon of teenagers sharing videos of themselves singing or dancing to popular music.

Users—or Musers as they are known on the app—create video selfies with a musical soundtrack and share them with friends. The most popular Musers have tens of millions of fans on the app and share revenue from brand partnerships with Musical.ly. The startup, which is based in Shanghai with an office in Santa Monica, Calif., has 60 million monthly active users, the company says.

The purchase price—in the range of $800 million to $1 billion, these people say—roughly doubles the valuation Musical.ly received in a 2016 round of funding. Investors in the startup include GGV Capital, Greylock Partners and Susquehanna International Group’s China arm.

Bytedance, best known for its personalized news app Toutiao in China, made the acquisition to find ways to coordinate content between the two platforms, and help its effort to expand overseas, a person close to the deal said.