Parents are often shocked by inappropriate videos on TikTok, a major hit with teens that Sensor Tower says was the most downloaded app on iOS in H1 2018 (Selim Chtayti/Agence France-Presse)

Selim Chtayti / Agence France-Presse:
Parents are often shocked by inappropriate videos on TikTok, a major hit with teens that Sensor Tower says was the most downloaded app on iOS in H1 2018  —  TikTok's video-sharing app was the most downloaded on Apple's App Store in the first half of 2018, beating out Facebook, Instgram and Snapchat