AdMob uses the Google Mobile Ads SDK. The Google Mobile Ads SDK helps app developers gain insights about their users, drive more in-app purchases, and maximize ad revenue. In order to do so, the default integration of the Mobile Ads SDK collects information such as device information, publisher-provided location information, and general in-app purchase information (such as, item purchase price and currency).
In this app, everything you need to do is to open Config.swift file and fill AdMob keys to make it work. AdMob SDK is allready installed in the app and you don't need to worry about this. Also make sure to put your AdMob Id in Info.plist file. If you don't do this, your app will crash.