To use Google Maps Image Downloader, you will first need to specify the latitude and longitude of the two locations on the Google Map, then specify the zoom level and click download.
The software also comes with an image stitching tool that will create a large panorama or a wallpaper by stitching these individual tile images of Google Maps.
See how to find the latitude and longitude of any location on Google Map.
The free version of Google Images Downloader is limited to a maximum zoom level of 13 so you'll probably miss the high resolution satellite imagery of Google Maps.
Invest $25 bucks only if you're sure that Google Maps Image Downloader isn't violating any of Google Maps policies especially the one that says - "you may not use Google Maps in a manner which gives you or any other person access to mass downloads or bulk feeds of numerical latitude and longitude coordinates."
Update: The creator has removed the tool.