Yep Dale, its graph paper.
I made this so if I was in a hurry, I could do a quick sketch of a room to scale, and figure sq. ft. at a later time. Especially if it was a weird shaped room, with lots of turns and niches, I could accurately scale it out and do figuring later. Plus, for wallpaper, I could send a guy out with the sketch, and say just hang this wall and there is no confusion. Also works well if I have a lot of rooms to measure at once, and its a good refresher in office for each particular area to compare to digital photos.
Like I said, its just a basic tool to help with estimating, nothing special.
BTW, Dale, are you the guy that makes/markets all those cool little tools?