Meta's AI companion app Muse has become one of only a dozen mobile apps to surpass 10 million U.S. downloads within 40 days of launch, according to market intelligence firm Sensor Tower. Since its September debut, Muse has accumulated 10.9 million downloads worldwide, 10.2 million of which came from the United States. The milestone puts the app in rare company: only 11 other apps have reached that scale so quickly, and the most recent was Meta's own Threads in July 2023.

A club dominated by games

Sensor Tower Senior Insights Analyst Kara Lee noted that the other apps to hit this post-launch benchmark were largely mobile games, including Fortnite, PUBG Mobile and Pokémon GO. Besides Threads, Disney+ was the only other non-game app in the group. That context matters for developers and product teams: reaching 10 million U.S. installs in under six weeks is a distribution feat usually reserved for titles with massive existing audiences or viral loops baked into gameplay.

Meta's advantage is its distribution machine. The company can market new products across a family of apps that now counts 3.6 billion daily active users. Threads was built on Instagram's social graph and its content was integrated into Facebook and Instagram, and Muse is benefiting from similar cross-promotion. But Meta is not relying on organic reach alone. Sensor Tower's data shows the company allocated 39% of its total advertising spend to market Muse in October, up from 23% the previous month. Muse now ranks as the 21st largest brand in the U.S. by advertising impressions this month, up from 73rd in September.

Retention beats rival AI apps

Marketing can drive installs, but retention is where AI apps often struggle. Muse appears to be holding users better than its main competitors. In the U.S., the app recorded a 30% retention rate after seven days and 23% after 14 days. By comparison, ChatGPT, Claude and Grok averaged a 19% seven-day retention rate and 16% at 14 days, according to Sensor Tower. Muse also hit 2.5 million daily active users for the first time on October 16, a 15% week-over-week increase.

The app, which can handle various tasks on users' behalf, has seen breakout success since launch. It shot to No. 1 on the App Store and at one point outpaced some of the metrics ChatGPT saw after its own launch. In its first 40 days, ChatGPT recorded 3.7 million U.S. downloads, while Grok and Claude saw only 500,000 and 200,000 respectively. Globally, ChatGPT reached around 15 million downloads in its first 40 days, but the comparison is not apples to apples: ChatGPT was available in multiple markets including Japan, Brazil and Germany, with Japan alone accounting for 25% of its global installs during that period. Muse is currently available only in the U.S. and Canada.

Store dominance and what comes next

Since launching, Muse has held the No. 1 rank on the U.S. App Store on all but one day, October 19, when streaming app Kick briefly overtook it. It has since reclaimed the top spot and has also been No. 1 on Google Play over the past 30 days. The download and engagement figures suggest Meta has found a formula for turning its massive social reach and advertising budget into a mainstream AI product, at least in North America. The open question is whether that momentum holds as the app expands beyond its current two-market footprint and faces the retention curve that eventually flattens for most consumer AI tools.