GitLab CI Lint - UI Enhancer is a free, open-source tool that makes it easier for you to manage your CI (continuous integration) pipeline on GitLab.com. It enhances your CI experience by making your script code multiline and syntax highlighting. It has been designed to work with the existing API on GitLab.com and can be used on any of the platforms supported by GitLab.com, including iOS, macOS, Microsoft Windows, Nintendo Switch, PlayStation, Xbox Live, Xbox One, and Android devices.

To start using it, you need to install it on your browser. To do that, you need to go to the download page on GitLab.com and download it. 

Once you install it, you will be able to use it in two ways. You can use it as an extension on your browser, or you can use it as a keyboard shortcut.