Twitter announced Wednesday that it is selling MoPub, the mobile ad platform it bought back in 2013, to mobile game and marketing software maker AppLovin for $1.05 billion in cash, as the microblogging platform looks to focus more on advertisements on its own app and website.

MoPub, which generated about $188 million in annual revenue for Twitter last year, allows companies to keep track of ad inventory in real time, comparable to Google’s DoubleClick. Twitter paid around $350 million for MoPub.

“This transaction increases our focus and demonstrates confidence in our revenue product roadmap, accelerating our ability to invest in the core products that position Twitter for long-term growth and best serve the public conversation,” Twitter CEO Jack Dorsey said in a press release.

The sale to AppLovin was unanimously approved by Twitter’s board.