I have an LG G3 Vigor phone. It is running Android 5.0.2. The Norton version is 3.17.0.3205. My problem is the amount of memory that it takes up. I am currently at 533MB. It is the larges user on the phone. It keeps on growing. The buttons to clear the data, or move to the SD card are both gray. What can be done to reduce the memory useage?