Safe for most kids
Line is a popular messenger app owned by the giant Internet search company, Naver. It is a popular alternative to WhatsApp, with the majority of its usage coming from Taiwan, South Korea, and Japan.

In-depth breakdown

Minimum Age Requirement
Messaging Capabillities
Line offers text chat, group chat, voice call, and video call. The popular trend is to send different cartoon stickers.
Location Sharing
Not available in-app. Line offers a sister app, ‘Line Here,’ that has location sharing features.
Parental Controls
Profiles of users under the age of 18 cannot be searched for by other users. Underage profiles have to initiate any line of communication, or share their user code outside the app.
Line prioritizes keeping their app as safe as possible for younger users; however, as with any messaging app, there is no absolute guarantee that a child will not encounter anything inappropriate.