Lookout may not use much in the way of resources, but whether it's needed is questionable .Programs like Clean Master and battery savers are virtually useless. After uninstalling both the performance of my Galaxy S4 improved. Unlike a PC an Android wants to fill up it's memory so programs can be quickly retrieved. As soon as Clean Master clears the memory, Android starts filling it again. Battery savers only turn off resources which can be done on your own. The chance of getting a virus is very small. These companies have done a wonderful job of making you feel like their programs are necessary, while at the same time separating you from your money.