Messaging app Line surpassed 100 million users in 19 months, according to a blog post on the official Line blog.

Line, an app developed by South Korea’s Naver Corp., is the leading messaging app in Japan. The app is now taking off in other regions, but in the grand scheme of messaging apps, the market is very fragmented with particular apps doing well in a certain country like Tencent’s WeChat in China and Taiwan Mobile’s M+ in Taiwan, and Facebook Messenger, WhatsApp and Kik in the U.S.

Line is a free app that allows users to send messages and initiate voice calls for free. American messaging competitors such as Skype have been allowing free calls for years, and recently Facebook added free voice calling to their Facebook Messenger app for U.S. users.

One of the newest messaging players is Digisocial, which is an iOS app that allows users to add audio to an image and to send voice messages for free through Digisocial’s network.

You can read our hands on with Line here.