Facebook requires it.
The California Attorney General’s office requires it. The California Attorney General’s office maintains that apps are obligated by California law to have privacy policies.
Know your partners. When using third-party code or software development kits (SDKs)—such as those from advertising networks or analytics—make sure you understand what the code is doing and the practices of those third parties.
Explain your relationship with analytics and advertising networks to users. Provide the appropriate notices and choices for users to opt out. Note that if you share information with your ad network that can be used to tailor ads elsewhere or if you display behaviorally targeted ads, you may be obligated to label those ads in compliance with the Digital Advertising Alliance’s (DAA) Self-Regulatory Program for Online Behavioral Advertising.
For detailed guidance, check out our App Privacy Guidelines page.