NewsGuard 5.4 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. The application lies within Internet & Network Tools, more precisely Browser extensions. This free Mac application is a product of NewsGuard Technologies, Inc.
From the developer:
NewsGuard uses journalism to fight false news, misinformation, and disinformation. Well-trained analysts, who are experienced journalists, research online news brands to help readers and viewers know which ones are trustworthy--and which ones are not. The Green-Red ratings signal if a website offers true or unreliable news.
You may want to check out more software for Mac, such as HealthGuard, which might be related to NewsGuard.