I use Pixelclean Wet and Dry packets for all my LCD screens for TV's and gadgets available here:
http://www.amazon.com/PixelClean-Wet...7585686&sr=1-3
On gadgets like the Fire only just touch the Wet Wipe to the middle of the screen and then clean with the Dry Wipe. TV's get a full rub down with the Wet before using the Dry.
I don't use protective covers on any of my gadgets and only use the wipes on gadgets when the dirt is noticeable. A little dirt doesn't hurt if you cannot see it. Never use the Wet Wipe near the edges of any TV or gadget.