Brian Kim, founder of South Korea’s top mobile-messenger operator Kakao, said he has pledged to donate more than half of his wealth to solve social issues, Yonhap News reported.

Kim, who once lived in a room shared with seven family members, has seen his wealth rise to $7.9 billion and now ranks 332nd on the Bloomberg Billionaires Index, a list of the world’s richest people.

“I have pledged to donate more than half of my assets to solve social issues throughout my life,” Kim told Kakao employees in a message, according to Yonhap. “I aim to solve social issues and help people that Kako has difficulty in approaching.”

Precise details of the donation have yet to be disclosed, though Kim is planning an official announcement, according to Yonhap.

Kim, 54, developed the Kakao Talk app in 2010 and controls a 26% stake in the company. Kakao has more than 45 million monthly active users and had third-quarter revenue of 1.1 trillion Won ($926 million), according to a company presentation.

This article was provided by Bloomberg News.