Firebase App Indexing (formerly Google App Indexing) is a system that allows people to click from listings in Google’s search results into apps on their Android and iOS smartphones and tablets. It gets your app into Google Search. If your app is already installed when users search for related content, they will launch your app directly from the search results. If users don’t have your app yet, an install card shows up in search results. Adding App Indexing promotes both types of app results within Google Search and also provides query autocompletions.