If you want to deploy measurement and advertising tags in a mobile app, you can use the Google Analytics for Firebase SDK. Once you deploy the SDK, you can also use Google Tag Manager to modify and route data.
What is a "tag"?
What is the Google tag?
What is Google Tag Manager?
In Google documentation, Google tag examples consist of
while Tag Manager examples provide steps to configure tags.
The following example illustrates the difference between use of the Google tag and Tag Manager.
This Google tag shows a snippet that you could add to each page of your website. The tag ID in the snippet enables measurement for Google Analytics and Google Ads.
window.dataLayer = window.dataLayer ||  ;
gtag( 'js', new Date () ) ;
gtag( 'config', 'TAG_ID');
To use Tag Manager to enable measurement for Google Analytics and Google Ads, you would create a tag for Google Analytics and a tag for Google Ads Conversions, which you would then configure to fire on the same trigger. After publishing the container, the changes are available instantly on your website. See Google Ads conversions to learn more.
Tags supported by Google tag and Tag Manager
The Google tag (gtag.js) and Tag Manager provide the following tag support:
|Google Analytics 4
|Google Analytics: Universal Analytics
|Google Ads Conversions
|Google Ads Remarketing
|Google Surveys Website Satisfaction
In addition to the Google measurement products listed here, Tag Manager supports a wide variety of third-party tags. The Community Template Gallery contains additional tag and variable templates maintained by third parties. You can also create and share your own tags with custom templates.