It depends on your business and app functionality. As we've written here [1], have a look at what Privacy Policies usually need to disclose:
- What kind of personal information you collect from users
- How do you use that personal information
- If you share this information with third parties
- If third parties can collect personal information through your app
- How can users access and change the personal information you collected
For example, if you're about to display ads through Google AdMob in your iOS app, then read AdMob Behavioral Policies [2]. At the "Personalized advertising" section, Google makes it clear that it may show interest-based ad to the users of your app and that any apps using AdMob must update their Privacy Policies to reflect this:
> Additionally, your app's privacy policy may need to be updated to reflect the use of personalized advertising (formerly known as interest-based advertising) served via the Google Mobile Ads SDK.
- What kind of personal information you collect from users
- How do you use that personal information
- If you share this information with third parties
- If third parties can collect personal information through your app
- How can users access and change the personal information you collected
For example, if you're about to display ads through Google AdMob in your iOS app, then read AdMob Behavioral Policies [2]. At the "Personalized advertising" section, Google makes it clear that it may show interest-based ad to the users of your app and that any apps using AdMob must update their Privacy Policies to reflect this:
> Additionally, your app's privacy policy may need to be updated to reflect the use of personalized advertising (formerly known as interest-based advertising) served via the Google Mobile Ads SDK.
[1] https://www.quora.com/What-do-privacy-policies-typically-inc...
[2] https://support.google.com/admob/answer/2753860?hl=en&ref_to...