Core Points - 91 Assistant, a mobile management application, will cease all services on September 27, 2025, due to business adjustments and product iteration needs [1] - Users are advised to back up their data before the service termination, as data will be permanently lost afterward [1] - Refunds will be available for users with active memberships, but they must apply for the refund by September 15, 2025 [1] Company History - 91 Assistant was developed and launched by NetDragon in 2007, initially gaining popularity as the largest iOS "jailbreak" platform, providing services like application installation and file management [2] - By 2009, 91 Assistant expanded to the Android platform, capturing nearly 90% of the domestic mobile assistant market [2] - In 2013, Baidu acquired 91 Wireless, the parent company of 91 Assistant, for $1.9 billion, marking it as one of the largest acquisitions in Chinese internet history [2][3] Market Dynamics - After the acquisition, 91 Assistant was rebranded as Baidu 91 and integrated with Baidu's mobile products, achieving a user base of hundreds of millions and a market share exceeding 50% in 2014 [3] - The rise of official app stores from Apple and Android manufacturers diminished the need for third-party tools like 91 Assistant, leading to a decline in its relevance [3] - By 2020, Baidu announced the discontinuation of 91 Assistant and the Android market, with the latest announcement marking the final closure of the product [4]