[Reply to mikestony,because Jhayzone,i don't have fqad or a chinese phone]
I don't have anything installed from these two.These are the "companies" found by searching the apps in Google Play Store:
App: Super File Manager - "Company":Onegogo
App: Super Locker - "Company":Augeapps
App: Doctor Clean - "Company":Kepoodev
(I think all of these apps,or at least the ones i've got in my phone,advertise APUS,not sure all of them though,but i'm pretty sure the design of these apps is pretty much the same as APUS,and two of them give my phone an extra screen to unlock,which look both the same,AND like APUS)
I've thought about the possibility of a malware copy of these apps which may be harmless in the original version,and NOT look the same in the original version.So i installed all of these apps on a different device from google play store.Their start screens still look the same,so i guess these three "companies" are a single entity in disguise.There may be malware in google play store,and i'm not surprised by that,but it's not normal that these apps install on my phone automatically.There is some virus there either from a random source or by this entity that keeps installing these apps,and i need to stop it.I don't know how to identify the source though.
Also,this just happened.When i used my phone like an hour ago some ads started popping out of nowhere while i was using other apps.I don't remember them well,but i think they also had the APUS style.The mentioned apps or any other suspicious app were not installed.This just started an hour ago,never happened before.Well,i guess i've got another problem.
Anyway,any way to find the source? i'm not good at seeing what are important apps essential for my phone to work and what are viruses(example:in the section of downloaded apps i had an app called settings an with icon that i've never seen before.I have literally never seen this app,but i don't know if it's part of my settings app or a virus)