Meta's Muse personal AI agent recorded 730,000 downloads over roughly five days after its September 8 launch, surpassing OpenAI's ChatGPT, SpaceXAI's Grok AI, and Anthropic's Claude in cumulative downloads during the same post-launch window. The app also became the leading free iOS app in the U.S. on Friday. Following the news, Meta's stock surged more than 11% on Monday.