The one downside to touchscreens is that they are always covered in fingerprints. Here is the perfect solution! Get a natural leather chamois, sold in the automotive aisles of most major supermarkets and cut off a small piece. If you have a phone case, you can store it right behind your phone. If not, cut it to the size of a credit card and sandwich it between two cards in your wallet.
This piece of chamois can last indefinitely as long as you care for it. To learn more about selecting the best cham and keeping it clean, see the guide Leather Chamois Cleaning and Care.