Google is changing the way it indexes apps in Search. It has announced the closure of Fetch As Google For Apps, a service it introduced in 2015, which may now interfere with Firebase App Indexing and cause duplication.
In a Google+ post, Google said the feature would be removed from the Search Console, and recommends app developers shift attention to Firebase App Indexing to ensure apps are indexed effectively.
Google acquired Firebase in 2015, and renamed its Google App Indexing service as Firebase App Indexing in May 2016. It helps users find an app in Google Search. New users will see a link to install the app, while those who already have the app can open it directly from the search results.
Visit Google’s Firebase App Indexing page here for more on how to use the service.