Apple came out with new thing called a "Polishing Cloth" which is a microfibre cloth for cleaning screen, being fruity it comes with a fruity price tag.
So now there's Smart Screen an antibacterial, microfibre smartphone cloth.
The pouch is about 2 inches square and holds the folded cloth which is attached by a piece of material and held by a popper.
Then the cloth unfolds
The cloth is impregnated with Blue Shield nano silver particles which (according to the manufacturer) will kill 99% of all bacteria and it will survive 15 washes at 30 degrees.
As a cloth it does clean screens (though it wasn't possible to test the accuracy of the bacterial killing properties).
It only costs £9.95 directly from Smart Screen, though an up market "gold" version is available for £11.50 (or a replacement gold cloth for £4.40).
Standard colours are Navy Blue, Slate Grey, Powder Blue, Saffron Yellow, Polar White and Camel Brown.
I would guess it's as functional as the fruity equivalent (though never tested that particular cloth).