One of the best parts of getting a new phone is how fresh, shiny and new it is — inside and out. The screen is scratch-free, your storage is blissfully empty and it runs like a dream. But before long, it loses its luster. Even if your phone is relatively new, it probably still needs a good cleaning. Over just a short period of time, things like cookies, location services and ad networks could start causing problems behind the scenes. They could even pose privacy and security risks.