What added material to cover glass front door. Thanks.

Home Depot sells privacy film that you cut to the size needed.

The Professional establishments use a type of plastic that goes on wet with a squeegee and can totally obscure the glass. It makes it appears as if there are shadows behind the glass, but they are unrecognizable. This type of film can be ordered and applied by non-professionals. Then there is the pretty, patterned films that are available at your local hardware stores. These are sold in specific sizes, so that you may have to purchase several, depending on how large an area you need to cover. And, lastly, there is the regular patterned contact paper that is almost opaque, but not quite. This can be applied to a clean window like you would apply wall paper, complete with a razor blade to cut it perfectly into the edges. Because it only comes in certain lengths and widths, some pieces may need to be overlapped or butted up against each other and seams will show. Short of replacing the glass with something opaque, these alternatives can save quite a bit of money. They are all definitely worth a try.

Glass paint, your own design if you're artistic....and stencils if you're not. You can do a leaded glass look: https://www.pinterest.com/pin/184436547214875947/

Frosted contact paper will make the glass look frosted and you can't see through it.

Yes, I agree with the cut to size adhesive covering from Home Depot, they have several choices and it works well. I've had it up a few years now.