It said it had introduced the technology to help people get better results when they search.
Often, it said in a blogpost, the best answers to a query were found in an app rather than a web page.
Initially nine apps have been selected to work with the streaming system as it is tested.
Bad experience
Jennifer Lin, Google engineering manager, said the firm started indexing information found in apps two years ago to bolster its larger corpus of search data.
About 40% of searches done via Google now turn up content found in apps such as Facebook, Instagram, Airbnb or Pinterest, she said.
Until now, Google has only answered queries with information that is available both on the web and in apps. Now, however, it is starting to show results that are only found in apps.
One example of when these results would show up might be when someone is looking for hotels during a spur-of-the-moment trip to an unfamiliar city, wrote Ms Lin in the blog.
Google said it was using an in-house developed streaming system to give people access to results in apps they do not have installed on their Android handsets.
This lets people try the app and use it as if it were installed, said Ms Lin. An experimental cloud-based virtualisation technology Google has developed underpins the streaming system.
Apps from HotelTonight, Useful Knots, Daily Horoscope and Gormey are among the first to be available via streaming.
Danny Sullivan, founding editor of the Search Engine Land news site, said the streaming system made visible a lot of information that was hard to get at easily.
"It's a bad experience to show links to an app that no-one can view unless they install an app," he said.
Plus, he added, it could mean data found in apps was now more widely available and could be put to other uses.
"Potentially, the new system could even cause some apps that might seem to lack linkable content, such as games, to consider app-only links," he wrote.
Streamed versions of apps are available via Google's own app and on its Chrome browser. Users must also be on a fast wi-fi connection and be using a handset running Android Lollipop or a more recent version. Lollipop was released in November 2014.
The test of the app streaming and search responses is currently only taking place in the US. Google has not said when, or if, it will be expanded to other parts of the world.
