Google's John Mueller announced on Google+ that Google is looking for those webmasters and developers who have deployed App Indexing in their Android apps already if they want to preview some new features.
He said:
We're looking for some more people to try out things around App-Indexing. If you have an app that's set up for App-Indexing, and want to try things out, we'd love to hear from you!
If you are interested, you can fill out this form. The form reads:
We're working on new things for sites & apps that use App-Indexing, and we'd love your feedback. If you have an Android app, have set up App-Indexing ( http://g.co/appindexing ), if you'd be ok with signing an NDA, and if you're keen on trying something out and giving us feedback, feel free to sign up here.
I wonder if these previews are related to Google Webmaster Tools? A few months ago they bolstered their app indexing reporting in Google Webmaster Tools. Also Android Apps with App Indexing benefit from the mobile ranking factors, even if they are not installed.
Forum discussion at Google+.
