Privacy policy and Terms of use in the mobile app?

Question

Law in IT

Good afternoon. I ask knowledgeable people to help understand. The mobile app will soon be released on the App Store and Google Play. It will use data: phone, email, access to the gallery / camera / storage. There is an internal chat and notifications.
Questions:
1) Where should the privacy policy be placed? It is logical that before the initial authorization, but after downloading a bunch of applications on Google Play, I saw that everything is different for everyone. Is there a difference in the requirements of the App Store and Google Play?
2) Perhaps there are some templates / samples for the "Privacy Policy" and "Terms of Use" for mobile applications that are suitable for the App Store and Google Play?
3) On sites, the privacy policy is always paired with a user agreement. In applications, almost nowhere did I see the second. Is it mandatory? Is there a template/sample