Need to get addressabilty to the IApplication object

I'm working on a server component that is being run and tested in ArcMap as a tool.
The code is running and we are getting results but not expected results.

Part of the process creates a cost array which we want to add to the map. I have the basics ONCE I HAVE A MAP, but to get the map I need to create the IApplication object.

So running as a tool without any ESRI templates in my code...how do I create the IApplicationObject for accessing the maps in ArcMap???

Thanks