Chinese app Tuber briefly granted Chinese internet users access to blocked foreign sites such as YouTube and Facebook, leading some to celebrate that Beijing was moving to allow a more open internet. But it promptly became unavailable on Saturday after going viral on Friday. Tuber is an Android app made by a little-known company that is 70 per cent owned by a subsidiary of China’s biggest cybersecurity firm Qihoo 360. Sporting a logo similar to that of YouTube, Tuber’s main page offered a feed of YouTube videos, and on another tab it let users go to Western websites including YouTube, Facebook, Instagram and Twitch, which are blocked by China’s Great Firewall . But there were some catches: before using the app, users needed to sign up with their phone numbers, which in China are linked to their national ID numbers – meaning real identities. And the app’s terms of service said that if users “actively watch or share” content deemed illegal, it would share their data with “relevant authorities”. The app also censored content on the foreign sites. Tests done by media outlets showed that searching “Xi Jinping” and “Tiananmen” generated no results. The app has been available for download since late September, according to a Bloomberg report , but its popularity soared only last Friday after a WeChat article introducing the app went viral. On Huawei’s app store in China, it was reportedly downloaded more than five million times before it was promptly pulled on Saturday. The app has since disappeared from app stores, and the downloaded app displays a message that says it is undergoing a system upgrade. It is not clear if Tuber was approved by the Chinese government prior to its launch, or whether government censors are the reason Tuber became unavailable. Qihoo 360’s founder Zhou Hongyi is a political adviser to the Chinese Communist Party. Another browser from the maker of Tuber – Sgreennet – which also offered access to blocked foreign sites, has also vanished. Tuber is not the first time a short-lived app has tried to give people access to blocked foreign online services in China. In November last year, an app named Kuniao claimed to be the first legal tool to let Chinese internet users skirt the Great Firewall, offering censored access to sites like Facebook and YouTube. It also disappeared shortly after attracting wide social media attention in the country.