On its second anniversary, Discord is announcing that it has reached more than 45 million users for its popular voice communications app for gamers.

By comparison, the company had 11 million users in July 2016. That means it quadrupled its growth in less than a year.

The Discord community now exchanges 200 million messages a day, and it has reached a peak of 4 million concurrent users. The app generates about 6 billion messages a month, and its largest server has 77,000 members. And it has 8.9 million daily active users.

Image Credit: Discord

The results represent a big turnaround for a company that was written off in gaming. Founded to make games, Discord pivoted into something that became far more successful.

Discord started its life as Hammer & Chisel. But that company didn’t have much luck with its pioneering iPad game, Fates Forever. It launched in 2014 as a mobile take on the popular multiplayer online battle arena (MOBA) games. It won a lot of praise, but it didn’t get traction with players.

So Jason Citron, the founder of Hammer & Chisel, made the tough choice of shutting the free-to-play game down and switching to something new. It was an emotional time, but the team came through, he said. The result was Discord, a free voice-communication chat app for multiplayer mobile games.

Citron’s Hammer & Chisel went through YouWeb’s 9+ incubator, which provided initial funding. Early investors included Accel, TWI, and IDG. Then the company raised another round of funding earlier this year from Silicon Valley venture capital firm Benchmark Capital and Chinese internet gaming company Tencent. It also raised $20 million in a round led by venture capital firm Greylock Partners in January 2016.

Citron previously got a lot of attention for building early mobile game company Aurora Feint, later called OpenFeint (as it morphed into a game services firm), in the early days of the Apple App Store. He sold it to Gree in 2011 for $104 million. That was an extraordinary, fast-moving experience for an entrepreneur who had his big pay day at the age of 26.

For much of 2015, Citron’s company worked on Discord. The networking infrastructure is built in Erlang, a technology that Ericsson created in the 1980s for telecommunications. The system is spread across nine data centers around the world. Discord has done tests to make sure that the latency is good.

Discord noticed that esports competitors — or professional gamers who play games for money prizes — were worried about security. With Skype, it’s easy to get somebody else’s personal internet protocol (IP) address because the communication happens peer-to-peer. Citron said that Discord works through server infrastructure, so it’s impossible for anyone to obtain another player’s IP address. If a voice server in the distributed cloud gets attacked by someone flooding it with data, it shifts the communication to another server.

Discord runs in a browser or as an app. So getting into the chat is easy as all you have to do is share a link and type in your username.