Installing this addon allows your browser to become a bridge for censored internet users, like in China, Iran or Syria. It does required no knowledge and works out of the box.
The extension's icon is usually colored green. It means everything is working and that it is now waiting for censored people to access it. Cyan means that someone is using it in this moment. If an error occurred, it turns red. In that case restarting your browser might help.
Oh and if you worry about running this in your browser: It is just an entry point. You won't be sending request to random websites, but only allow people access to the Tor network. An exit relay will take care about that.
The bug tracker and source code can be accessed via GitHub
More information about the technology behind it can be found on the website of Flashproxy