"It’s important to sufficiently disclose to users how your app will use ads. You must make it easy for users to understand what ads will be shown in your app, where they will be shown, and what the associated behaviors are, if any. Further, you should ask for user consent and provide options for managing ads or opt-out. Here are some guidelines:
Tell users about your ads—Create a simple, complete disclosure that tells users how your app uses ads, where the ads are shown, and how they can manage ad options. Take common-sense steps to make the disclosure as clear as possible.
Make sure users know—Present your ads disclosure is an easy-to-see location, rather than hiding it where users are not likely to find it.
Ask for consent (opt-in) at launch—Where possible, include your ads disclosure in the app description as well as in an Ads Terms, End User License Agreement (EULA), or similar document. Display the terms at first launch and ask for the user’s consent before continuing to the app."