This one is just made by sewing together two pieces of cloth. They were shaped like a rectangle with one half having a larger width. They are then folded in half before sewing the unconnected sides (minus the top of course). Add a flap with a button hole and a properly positioned button and it is finished.
I chose to use a soft microfiber cloth for the inside so that I knew the screen wouldn't get scratched. You could really choose any outside fabric style you like. I just happen to like brown, dark reds and oranges (anything fallish). It didn't cost me anything because my mother who likes to sew had all these materials as scraps. Cheaper, more unique and more sturdy than something I would buy online.