Line, a messaging app made by South Korea's Naver Corp. that took off in Japan, just crossed 100 million users globally 19... moreLine, a messaging app made by South Korea's Naver Corp. that took off in Japan, just crossed 100 million users globally 19 months after it originally launched. The app is one of the leading contenders in smartphone messaging in Asia and faces off against Tencent's WeChat and KakaoTalk.