And you would have to dig in and learn forensics and more. There is no short treatise on the subject but many apps need access. Especially if you have yours set to backup or sync. In fact I bet most of the complaints like this are not spyware but just the phone backup to the cloud or PC.
In "my activity" history on Google, two apps were accessed numerous times on specific days, zero on others. For example, on my birthday Pics Art was used 16 times within a 3 hour time frame. I know I did not use it as I recall the day clearly. Camscanner is the other app. Some days these apps were not used, other days 10-40 times. Often at hours I was sleeping. My activity on Google says "ads" accessed these apps. It's odd "ads" looked on days I was in disagreement with the ex.
Is there a specific program that uses ads or current apps in your phone to access files/camera, etc?
Why I'm asking...
After months of having suspicion my Ex had some type of access to my phone, I discovered he was paired to my Bluetooth. Tech remote accessed phone, cleared the connection, and deleted a couple of apps. They said if a program was used with this pairing, he could have had complete access to my phone, however it's hard to find. After that I searched my history and files, the apps above is all I've found and can't explain.
I've seen the terrible tracking programs sold online. I'm just trying to see if this was actual access from a remote program or paranoia. In search of peace of mind.
Thanks for your help.