Google has been trying to heavily promote App Indexing, we covered it here several times, it is basically a way for you to tell Google about content within an app and have it potentially be indexed and rank in Google’s search results. Even better, if you are on an Android phone and click on the search result, it would take you directly to the content within the app, as opposed to a web page.
That being said, Google wants to answer your webmaster and technical questions around App Indexing. Mariya Moeva from Google posted about it on Google+ last week saying:
So far, only 1 person has submitted 2 questions – so it needs some help. App Indexing is cool and truth is, I would have implemented on many of my Jewish Android apps but I haven’t yet many because Google has a pattern of adding cool new indexing and SERP features and removing them a few years later. If and when they support iOS, then I may begin to add them, that would be a sign they are serious about it.
Any event, it is worth asking your questions at Google Moderator.
Forum discussion at Google+.