Google Webmasters Drive app installs through App Indexing. Posted: Thursday, April 16, 2015
Not sure if this got shared out this past week. Basically:
"App Indexing has already been helping people engage with your Android app after they’ve installed it — we now have 30 billion links within apps indexed. Starting this week, people searching on Google can also discover your app if they haven’t installed it yet. If you’ve implemented App Indexing, when indexed content from your app is relevant to a search done on Google on Android devices, people may start to see app install buttons for your app in search results. Tapping these buttons will take them to the Google Play store where they can install your app, then continue straight on to the right content within it."