PreviewJson provides QuickLook file previews and file icon thumbnails for documents encapsulating the popular JSON format. You can view previews with or without JSON object and array markers, choose your preferred level of indentation, the preview presentation font, and the colour of object keys.
The app provides two app extensions: JSON Previewer and JSON Thumbnailer, which can be viewed and managed in macOS’ System Preferences > Extensions. The app itself is a container for these extensions, and is used to set your preferences.
You must run the app first to gain these benefits.
• Add link to PreviewText.
• Better menu handling when panels are visible.
• Better app exit management.
• Bug fixes.
PreviewMarkdown 
PreviewCode 
PreviewYaml 