According to the documents, Youge’s executive director is a woman named Zhang Jingmei. She appeared in a photo of a recent meeting between Facebook and the Shanghai government, sitting next to Wang-Li Moser, a Facebook executive whose responsibilities include building up the company’s relationship with the Chinese government. Ms. Zhang’s presence at such a high-level meeting indicated she is likely a Facebook adviser or employee.

Facebook declined to comment on Ms. Zhang’s relationship to the company, and Ms. Zhang did not respond to phone calls requesting comment.

If Facebook did little to promote Colorful Balloons in China, it did work to tailor the app to a local audience. In the rest of the world, the company’s Moments app connects users through Facebook. Colorful Balloons instead links users through China’s biggest social network, WeChat.

The app, which is designed to collate photos from a smartphone’s photo albums and then share them, does so in China with the use of a QR code, a sort of bar code that is widely used by WeChat and other apps in the country.

While photos can be shared, Facebook appears to have taken steps to ensure the app could not spread widely. For example, people who post photos from Colorful Balloons on WeChat will see a link that lets other users download Facebook’s Chinese app. But the link does not work, meaning people have to seek out Colorful Balloons in an app store instead of grabbing it from their friends, which may limit its distribution.

The risk Facebook is taking with the new app is high. The company appears to have handed over a fully functioning product to Youge for release, and has done so without indicating in any public way that it is connected to Facebook. Coming just ahead of a key meeting of the Chinese Communist Party this autumn, the secretive release of Colorful Balloons could also undermine trust between the company and the Chinese government.

Such tactics underline the degree to which Facebook is willing to experiment and break precedent to get into China. Last year, The New York Times reported Facebook had also quietly been at work on a censorship tool that could be used on a version of the social network in a place like China, where the government demands control over what is shared. The tool could suppress posts from appearing in people’s news feeds in specific geographic areas.