^ Diamond dust LOL kidding
well its not my phone but my cousin's i`d occasionally burrow it from time to time and using the stylus leaves trace marks on the screen protector(cheap one), nails leaves scratch mark too.
he did once tried one of those effing expensive screen protector, cool it lasted two months... then he thinked back, once a week for 10% of the price, he`d be saving 20% worth of money.
ps: he`d change it before the scratches becomes heavily visible, thats why he`d change it once a week, he could stretch it to twice a week if he wasn't that much of a perfectionist.