How Facebook know what apps I have installed on my iPhone and iPad?

[anon(4216826)]

Dear iMore community,

In the light of the Facebook scandal i looked in the ad preferences tab on their website.

I am confused about the fact that somehow Facebook knows what apps I have installed on my iPhone and iPad.

In the "Your interests" settings page on Facebook it shows that I have installed Brilliant app, Duolingo and Coursera.

I do not have Facebook or Facebook messenger installed on any devices. I never logged into those apps with my Facebook user account. I am using email for any logins in the apps. I never liked any pages related to those apps.

How in the hell can Facebook determine that I have those apps installed?

Thanks, Paul

 

[msm0511]

How long have you been using iOS devices? A few years ago Apple had agreements with FB and Twitter that integrated the apps more deeply into the OS. They stopped that in iOS 11. So if you used FB on an Apple device before iOS 11 that's probably how they know.