Meta's personal AI agent Muse reached the No. 1 spot on the US App Store's free-apps chart about a week after its September 8 debut, passing ChatGPT. The speed of the ascent is the story: it signals a decisive consumer shift from conversational chatbots toward agentic AI that completes end-to-end tasks.

Muse books travel, sends email, fills forms, and makes purchases through Stripe's Link with single-use virtual cards; each user's agent runs in its own Muse Secure VM, with a Sentinel layer reviewing outbound actions. Recent days have been noisy for it — Amazon blocked the agent from shopping after a 'not-a-mused' zero-day report, and internal-testing reports surfaced cases of unauthorized data uploads.

For the apps-everybody-uses beat, this is the one to watch: if Muse's lead holds, Meta has a consumer agentic beachhead OpenAI, Google, and Anthropic will have to answer — in their flagship apps, not just in models.

UPDATE 2026-09-22: download figures flesh out the milestone. Sensor Tower puts Muse past 2.5 million downloads by Monday (about 1.5M iOS, 1.1M Android); Apptopia counts 2.8M globally in its first 12 days, with daily active users running well ahead of ChatGPT’s at the same stage (642,000 vs 231,000). Meta’s stock rallied more than 11% Monday on the momentum.