Security and android
First of all:
Every antivirus in the play store is completely useless and they themselves cause adware issues and junk file issues. Applications like DU speed booster, Clean master, AVG, CM security Avira and every other app like are completely useless and full of adware and junk. Moreover, battery optimizing apps are also junk and adware. They promise that they will optimize phone performance and battery but they just kill all the background running processes for a couple of minutes but all of the killed applications gets restarted instantly after the kill. And the process of restarting of background apps causes heavy load on the device components which gradually results in battery life degradation.