Entry Door Window, how do I get privacy at night?

I found at Home Depot, a plastic window covering in various designs and colors. All you do is wet it, the apply to a window. And it stays in place. We have had it installed in our 5 er for 11 1/2 years, and that included the hot sun beating down. And they, that is Home Depot, still have it. I saw it there about a month ago in the area of window coverings, rugs etc.