You should regularly clean the screen with a microfiber cloth as a dirty screen can affect the performance and responsiveness of the screen.
To properly clean the screen:
- Turn off the system by pressing and holding the Home button (the oblong button located at the bottom of the screen)
Note: The cloth should be free of sand, dirt, or anything abrasive that may damage the screen. Do not use rough cloths, paper towels, or tissues as these can scratch the screen. Only apply light pressure on the screen when you are cleaning it as pressing too hard can cause damage. Do not spray liquid or corrosive chemicals on the screen. Do not use window cleaning liquid, cleaning agents (particularly ones containing abrasives), sprays, solvents, alcohol, or ammonia to clean the screen. You may also view a how-to video on how to clean the screen here.