What data can be obtained about the user of the mobile application?

Question

Mobile development

What data can be obtained about an unauthorized user on the very first visit to the mobile application?
For example, in a browser on the web, you can get the referrer of the transition, source / channel by UTM, user agent, screen size, etc.
What of this kind can be obtained by default about the user in the mob. application? What user data is stored by default on the side of the application itself?

Answer 1

device id
depends a lot on permissions, but at least the list of contacts and all media