More than 30 million users signed up for Meta’s new app Threads, designed as a direct rival to Twitter and the most serious threat yet to Elon Musk’s struggling social-media site.

On Threads, people can post text and links and reply to or repost messages from others. The app will let users port over their existing follower lists and account names from Instagram, Meta’s photo and video-sharing app that counts major brands, celebrities and creators among its more than 2 billion users.

"There should be a public conversations app with 1 billion-plus people on it,” Meta Chief Executive Officer Mark Zuckerberg said in a post on his Threads account. "Twitter has had the opportunity to do this but hasn’t nailed it. Hopefully we will.”