Meta's Muse AI agent tops U.S. App Store and launches Mac version with file‑handling capabilities

SentiSense · Published Sep 18, 2026, 11:22 AM ET · Updated Sep 28, 2026, 2:45 AM ET

Meta's new Muse AI agent surged to the No. 1 spot on the U.S. iPhone App Store, overtaking ChatGPT and Grok, according to multiple sources. The app quickly expanded to macOS, where it can access and act on files, messages, calendar entries, notes, and email. Reviews note its powerful assistance but raise privacy concerns over deep integration with personal data.

Meta unveiled its Muse AI agent as a surprise hit, propelling the app to the top of the U.S. iPhone App Store and displacing rivals like ChatGPT and Grok within days of launch. TipRanks highlighted the rapid ascent, confirming Muse's No. 1 ranking on the App Store chart.

Following the mobile success, Meta extended Muse to macOS, allowing the assistant to interact directly with native applications such as Files, Mail, Messages, Calendar, and Notes. The TechCrunch report details the Mac version's functionality, noting that users must opt in for each permission and that Muse always prompts before accessing sensitive data.

Early hands‑on impressions from Business Insider describe Muse as a "very powerful" personal assistant capable of organizing inboxes and handling routine tasks, yet the reviewer flagged frequent failures with school‑related forms and voiced concerns about granting the app access to email, credit cards, and health data. These privacy and reliability questions underscore the trade‑off between convenience and data exposure.

The combined coverage suggests that Muse is poised to become a central Meta product, potentially reshaping user expectations for AI‑driven productivity tools. Analysts will watch adoption rates on both mobile and desktop, as well as any regulatory scrutiny stemming from the depth of data access required for the agent's functionality.