Meta’s Twitter-rival app Threads is set to launch Thursday in what could prove to be the biggest challenge yet to Elon Musk’s social media platform since his takeover last year. Threads will let Instagram users keep their followers and username on the new app and appears to be a free service. The long-awaited launch comes after Musk imposed increasing restrictions on Twitter for non-paying users. On Monday, Twitter announced that its previously free dashboard TweetDeck would only be available to paid verified users in 30 days. The move came after Musk over the weekend began limiting the number of posts Twitter users could see on a daily basis, with existing unverified customers restricted to 10 times fewer than the amount permitted to paying users. He said the new restrictions were meant to address “extreme levels of data scraping & system manipulation” on Twitter.