Clubhouse will begin introducing a test version of its exclusive live chat app to Google's Android users in the US on Sunday, the company said, in a potentially big expansion of its market. The app, which spiked in popularity early this year after celebrity billionaire Elon Musk and others appeared in audio chats, has sparked copycat software from start-ups and larger rivals including Facebook and Twitter. Part group chat and part radio, <a href="https://www.thenationalnews.com/business/technology/what-is-clubhouse-and-why-is-it-suddenly-so-popular-1.1165709">the social media platform</a> allows people to chat in theme rooms that disappear once the conversation is over. It has been available only to users of Apple devices and by invitation. In some markets, such as China, invitations were so sought after that some were auctioned on online marketplaces. But downloads of the app, one measure of popularity, have significantly fallen. After peaking in February with 9.6 million downloads, that number fell to 2.7 million in March and then 900,000 downloads in April, according to market intelligence company Sensor Tower. The drop has sparked questions about Clubhouse's long-term viability and whether its success was owed in part to people spending more time at home during the pandemic. The long-anticipated Android launch is expected to reach more new users globally. The Android version will reach other English-speaking markets and then the rest of the world days and weeks after the US market beta launch, though confirmed release dates have not yet been given. Clubhouse, which created the category, now faces the likes of Facebook, whose chief executive <a href="https://www.thenationalnews.com/business/technology/facebook-to-reportedly-launch-new-social-audio-products-1.1206647">Mark Zuckerberg announced in April</a> a slew of audio products, including Clubhouse-style live audio rooms and a way for users to find and play podcasts. In January, Twitter said it will introduce a new feature to let users charge admission to their live audio chat rooms in its "Spaces" feature, as the company seeks to court more content creators. The feature has been available to Android users since March.