The 1.8.1 version of Jayson for Mac was available as a free download on our website. The application is included in Design & Photo Tools. The actual developer of this free Mac application is Christian Kienle.
From the developer:
Jayson is displaying the contents of a JSON file in an outline view. Well you already know how to use an outline view since it is a standard macOS control used in Finder, Xcode and many other apps. You intuitively know how to use the most important features. Although there are many small hidden features that make your life easier.
You may want to check out more software for Mac, such as PulpMotion Advanced, I Can Animate or Corel Painter Sketch Pad, which might be related to Jayson.