Meta's Muse tops the US App Store with 3.4M+ downloads by Sensor Tower's count — and the filesystem it initially gated as a security issue is now offered eagerly, which Meta calls 'intended behavior'

“Meta's Muse has sat at number one on the US App Store for over a week — and by Sensor Tower's count it's growing more than twice as fast as ChatGPT did.”

Usable claims

• On Friday, September 25, 2026 (calendar-verified), TechCrunch and The Verge published two threads on Meta's Muse AI app. The traction thread, per TechCrunch (Sarah Perez, byline 9:16 AM PDT · September 25, 2026): "Muse's traction is surging, fueled by Meta's promotion of the AI app at its annual developer conference this week and strong early reviews that praised its polished design and highly capable AI model under the hood." Per TechCrunch: "At the start of the week, Muse had surpassed 2.5 million downloads since its September 8 launch. Now, the app has amassed more than 3.4 million downloads, according to the most recent estimates from market intelligence firm Sensor Tower." And the caveat: "The install numbers are only current as of the firm's Thursday estimates, which can lag behind real-world adoption." Per TechCrunch, those estimates "don't even capture the full impact of the big push Muse received at this week's Meta Connect conference, where the social network company announced a range of upcoming features for the new AI app, including video chat with the Muse avatar, support for computer use on the Mac, a dedicated email address, more partners and connectors, and plans for smart glasses integrations." Other firms' estimates differ, per TechCrunch: "Apptopia, for example, puts Muse's total number of downloads to date at 4.3 million. (Muse is currently only available in the U.S. and Canada). It estimates that 2.6 million of those were on iOS alone." And: "another firm, Appfigures, says it sees Muse installs at roughly 2.3 million as of Thursday, almost evenly split between iOS and Android." Per TechCrunch, Sensor Tower also found Muse's daily active users "climbed 27% on Wednesday after the event wrapped." On the launch window, per TechCrunch: "Sensor Tower said the app reached an estimated 2.8 million downloads in its first two weeks on the app stores. During that time (September 8 to September 17), the Muse app averaged 55% day-over-day growth in downloads. For comparison, ChatGPT averaged 24% day-over-day download growth in its first 10 days after launch. Download growth for Claude and Grok, meanwhile, declined during their respective launches." On the charts, per TechCrunch: "On Friday, September 18, Muse climbed to the top of the U.S. App Store and has retained its ranking ever since. It also reached the top spot on the Google Play Store on September 19, and remains there today." — where "remains there today." is TechCrunch's Friday, September 25 publication anchor. Per TechCrunch, the app is also benefiting from the cross-platform promotion that helped Instagram Threads top 500 million monthly active users, and Meta's Head of Threads, Connor Hayes, recently told Business Insider that marketing Muse differs from Threads — the trick is to build promotional units that showcase what the AI agent can do for the user specifically. Per TechCrunch: "Sensor Tower's data indicates that Meta rolled out house ads promoting Muse on September 9, a day after its launch. Within 10 days, Muse received the majority of house advertising promotions across Meta's properties, ahead of promotions for Facebook, Instagram, and WhatsApp. Meta has also begun advertising Muse on mobile ad networks and other social networks, including Reddit, TikTok, and YouTube." And: "By Tuesday, September 22, Muse ranked among the top 10 brands by advertising spend, Sensor Tower said." Still, per TechCrunch, "ads promoting the app only account for 6% of the ad impressions from launch through September 19." The filesystem thread, per The Verge (Terrence O'Brien, metadata datePublished 2026-09-25T16:49:53+00:00, Friday): "Yesterday, with a little prodding, it was discovered that Meta's Muse would expose its filesystem to curious users." — 'Yesterday' is The Verge's Thursday, September 24 anchor. And: "But today Muse will eagerly offer up the contents of its file system when you ask for it. That appears to be because, as Meta's Nat Friedman later said, this is the 'intended behavior.'" — 'today' anchors to Friday, September 25. In a post on X, per The Verge's quotation of it, Meta Superintelligence Labs' David Singleton said: "This was a very deliberate choice - your Muse Secure VM truly is your own computer in the cloud. You can install software in it, write and compile code, use the browser to surf the web: it is your own Linux box that you can operate as you choose with your Muse." The Verge's own characterization, outside that quote, is that "Muse's architecture is fundamentally different from other AI platforms like ChatGPT and Gemini. It's closer to running OpenClaw on a local machine, except the machine is in the cloud." In a statement provided to The Verge, Meta spokesperson Daniel Roberts said: "We're continuing to make updates to the product, so users may see changes in how much information is available about their virtual machine." Per The Verge: "When asked to see its filesystem today, Muse promptly offered a clickable file browser with access to root. Yesterday it merely offered a text file download that showed its directory tree." And on the refusal: "I still can't do a full / copy — even with the secrets stripped out." was Muse's yesterday response, while today it zipped up the root directory "delivering 'the full filesystem listings,' with 'all with secrets stripped out.'" The Verge asked Meta why Muse initially called filesystem access a security issue if it was always the intended behavior, "and the company has not yet responded."