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.
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.

The ITV2 show sees single men and women put together in a Majorcan villa to find love and win a Â£50,000 prize.
So far this series, there have been several instances of, shall we say, intimate behaviour taking place.
But broadcasting regulator Ofcom says it has actually received far more complaints about scenes that show the contestants smoking.
The series airs after the 21:00 watershed but has still attracted 46 complaints to date.
More than half of those - 24 - were from viewers objecting to the portrayal of smoking.
Fifteen of the complaints were made about the promotion of "sexual material and promiscuity".
The remaining complaints were for bad language, grievances about a racial slur and violence (for the time when a contestant threw a cushion "aggressively").
Ofcom has said it will assess the 46 complaints before deciding whether to investigate further.
The ITV2 show has a large following and an audience that includes pop singer Adele.
Speaking at the second of her Wembley dates last week, she labelled one of the contestants a "tramp" for taking part in a show in which "real people have real sex on real TV".
Falling in love isn't easy - let alone falling in love on national television, writes entertainment reporter Genevieve Hassan.
But that's what 13 sexy singletons hope to do on Love Island, which is halfway through its third series on ITV2.
If you've never seen it before, the premise is to couple up and convince the public to keep you on the island in order to win Â£50,000 - all while trying to find your perfect match.
Think Big Brother but with board shorts, bikinis and more under-the-sheets shenanigans than you can shake a stick at, as the couples chop and change throughout the series.
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Google has started streaming apps to Android phones so people can use them even if they are not installed on a handset.
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Viewers have been complaining about Love Island - but not for the reason you might think.