Google's Gary Illyes said in a Google hangout with Stone Template Consulting yesterday that the engagement levels on the App Install button for those app developers who integrated Google App Indexing is very low. The engagement levels are so low that Google decided to pull the resources working on that and move them to a new feature.
As you know, the Google Search Console added analytics for app install button clicks and the data that I see is incredibly poor myself for our app (which I recommend you all install, it is really good).
Here is my graph, you can see in the last 28 days I had four clicks on the app install button in the Google search results:
Gary said at the 26:20 mark into the video:
Not much changed [with Google App Indexing], as far as I know. But, if I remember correctly, the engagement on those app install buttons weren’t high enough or there weren’t enough engagements to spend more resources on it. We just moved them to another feature as opposed to spending more resources on it and maintaining it.
At 24:50 he said "to be frank, I don’t think we are doing much with it," referring to App Indexing.
Truth is, I am not sure how involved Gary is in App Indexing because I am doing a panel on it at SMX West and we have Google's Mariya Moeva on that panel to discuss things. So we will see.
Forum discussion at YouTube.
Update: I asked Mariya, as mentioned above, for feedback on this and she added:
+Barry Schwartz the app install buttons in search results are not going away (: - here's one I got just now: http://prnt.sc/a2ch6g. However, we want to make sure we show app results only for queries where the user intent is very strongly app-seeking, so we're constantly running search experiments (as usual for everything in search!). I'm guessing what Gary was referring to is an experiment where we showed install buttons for indexed apps for a broader range of queries, which we eventually turned down.
Generally, our resources are still very much focussed on helping users discover and download useful new apps — see for example app streaming (http://goo.gl/Oefc4w) and app blocks in results (http://goo.gl/8iZjH1). And as always, the most interesting is ahead (: