Google describes the rules for Firebase as:
You are required to notify your App Users by disclosing the following information:
- The Google Analytics for Firebase features you have implemented.
- How you and third-party vendors use first-party cookies, or other first-party identifiers, and third-party cookies and similar technologies, such as identifiers for mobile devices (including
- Android Advertising ID and Advertising Identifier for iOS), or other third-party identifiers, together.
- How App Users can opt-out of the Google Analytics for Firebase features you use, including through applicable device settings, such as the device advertising settings for mobile apps, or any other available means.
I'm not sure how to read the last point. Does a developer that uses Firebase (especially one located in the EU) has a duty to provide every user with a way to opt out of Google Analytics?