You may have never heard of TikTok, but chances are the kids in your life have. The China-based social network made its U.S. debut in 2017 and now counts 104 million American downloads (1.2 billion worldwide). Since January, it has consistently ranked among the top three most downloaded apps, behind Facebook-owned duo WhatsApp and Messenger. The average user now spends around 45 minutes a day on TikTok, more time than they even spend on Facebook. What’s the appeal? On its surface, TikTok is pure social media candy that’s highly addictive to its tween audience, according to user data analyzed by App Ape. Users make 15-second videos (think funny dances, pranks, and lip-syncing bits), then use TikTok tools to incorporate music and effects. (Here’s what’s trending today.) They can then publish their creations to the whole world, YouTube-style. One of the best-known TikTok stars is Lil Nas X, whose Billboard-topping hit “Old Country Road” got its start on the platform. Read more at Fast Company.