With Adobe Extension Manager you can install and manage new extensions.
For Adobe InDesign CS5/CS5.5/CS6 only BigPicture gives you the most comprehensive solution for managing graphics and picture links in Adobe InDesign..
Combines the editing power of Google Docs with the layout power of InDesign.
I have downloaded the full version on Mac. I am using Indesign CS6, but it is not shown in InDesign.
I have tried to download the application and come to the official installation instructions instead. There is a page created by the developer that explains how to install it on your Mac.
Install instructions: http://www.croptima.com/help/inplate/v2/install.html
Note: Adobe Air is necessary to be downloaded (Windows/Mac compatible) in order to have the software registered properly.