So if you have a web site and an Android app, you can create deep links from your site to your app and Google will link from the search results to your Android app directly to the specific piece of content within the app.
Google will then automatically crawl and find those deep links without you having to request white listing.
Google also added debug details and reports to Webmaster Tools for this new feature. The report will show you issues related to app page-web page pairs, together with example app URIs. Here is a sample report:
Plus they will give you debug instructions on how to fix the issue via code and QR code:
My feelings, this won't last, just like so many other things Google introduced. You can 100% benefit from it in the next few years but ultimately, I feel Google will drop this feature, like they've dropped so many others.
Forum discussion at Google+.