Google Play is now letting developers appropriately index the content within apps so they can be integrated into Google Search. Google can now search within apps, including deep links to the content within the application. For instance, a search for a recipe might yield results to a cooking site as well as a deep link to a recipe within the Epicurious app. Expect this to increase discoverability and have search lead to deeper app engagement.
According to Google: “App Indexing helps you drive usage of your app through Google. Deep links to your app appear in Google Search results on Android so users can get to your native mobile experience quickly and easily.”