Is gDocBinder available for a Mac Air?
No, the gDocBinder is an application developed exclusively for the Windows operating system. As you can see below, the software has been developed to run only on certain Windows versions. Check the image to see the list of these versions.
Official website: https://www.nikecstore.com/the-digital-binder/
However, on the OSX you can install Windows through the Bootcamp or the Paralells Desktop. These apps virtualize Windows in native mode or in a Window.