The app is applied to objects such as grid callouts, arrows, break lines, etc. that the user wants on the edge or extent of the active viewport.
Moving objects towards the extents or edge of the active viewport is not an easy task, such that you have to create the outline of the specified viewport, put it on model space by using the PSPACE command, go back to the Model tab and locate the outline created, move your objects towards the outline created and go back again to Paper Space.
This app does the job at ease in just a simple object selection and a few clicks to achieve the desired result.
A sample GIF image below is provided.