Chrome OS Tree Status is a free Chrome extension developed by the Chromium OS Developers. It provides users with a convenient way to check the openness or closedness of the Chrome OS build tree. The extension adds an icon next to the combo-bar, indicating the current status of the build tree with green or red color. By clicking on the icon, users can instantly access the build tree.

One of the key features of this extension is the ability to customize the build status URL. This allows users to point the extension to a different build status source if desired.

The latest version of Chrome OS Tree Status, version 5.0, introduces the ability to display notifications to sheriffs. This feature enhances the user experience by providing important updates and information directly through the extension.

Overall, Chrome OS Tree Status is a useful tool for Chrome OS users who want to stay updated on the status of the build tree. Its simple interface and customizable options make it a convenient addition for those who rely on the Chrome OS platform.