AdMob is now part of Firebase.
The Mobile Ads SDK for iOS utilizes Apple's advertising identifier (IDFA). The SDK uses IDFA under the guidelines laid out in the iOS developer program license agreement. You must ensure you are in compliance with the iOS developer program license agreement policies governing the use of this identifier.
Using CocoaPods makes it easier to manage library dependencies for your Xcode projects.
We provide a number of sample apps that demonstrate the use of the Google Mobile Ads SDK. You can find these open source applications at this GitHub repository:iOS samples