What will be purpose string of NSUserTrackingUsageDescription for Firebase/Crashlytics & Firebase/Analytics?

Question

As Apple requires developers to receive the user's permission through the App Tracking Transparency framework to track them or access their device's advertising identifier (IDFA) With iOS 14.5

I am using 'Firebase/Crashlytics' & 'Firebase/Analytics' in my app for crash reports. So I added below purpose string into my info.plist

<key>NSUserTrackingUsageDescription</key> 
<string>This identifier will be used to collect Crash Data.</string>

But still they rejected app with below reason.

Guideline 5.1.1 - Legal - Privacy - Data Collection and Storage


We noticed that your app requests the user’s consent to access the AppTrackingTransparency framework, but doesn’t sufficiently explain the use of the AppTrackingTransparency framework in the purpose string.

To help users make informed decisions about how their data is used, all permission request alerts need to specify how your app will use the requested information.

Next Steps

Please revise the relevant purpose string in your app’s Info.plist file to specify why your app needs access to the user's AppTrackingTransparency framework. Make sure the purpose string includes an example of how the user's data will be used.

You can modify your app's Info.plist file using the property list editor in Xcode.

Can someone please suggest to me, which string I need to add as a purpose string for this one? So it can sufficiently explain the usage.

Also, I found Add In-App Messaging to your app from google document.

https://firebase.google.com/docs/ios/supporting-ios-14

But have some doubts about this one so someone please let me know is it the correct solution and I need to implement it or it can be possible by just updating the purpose string.

Answer 1

Make it more detailed. You can say something like This identifier will be used to collect Crash Data and in-app activity in order to improve functionalities and user engagement . Or something alike.

In your String you only make reference to Crashlytics but you're missing reference to Analytics .

It is possible that Apple answers back saying something like they didn't find the Alert in your app after doing the correction of the String. If that happens, you just have to answer them that the alert only shows once per device (if so), and the class where you display the alert (commonly used in the AppDelegate ).