Google has finally announced actual sales figures for its Chromecast streaming stick: Consumers have bought 17 million Chromecasts ever since the device got first introduced two years ago, announced Google’s senior VP of products Sundar Pichai at the company’s I/O developer conference in San Francisco Thursday.

And those 17 million devices are getting used, a lot:  Chromecast users have cumulatively hit the cast button 1.5 billion times, said Chromecast VP of product management Mario Queiroz during a recent interview. That’s up from one billion casts in January. Active Chromecast users are now watching 66 percent more content than at launch, and YouTube alone has seen viewing time go up 45 percent after a user activates a Chromecast device.

Google didn’t unveil any hardware upgrade to the $35 streaming stick at the event, but Queiroz did note that there are some significant software tweaks that should make using Chromecast with a wide variety of apps more interesting.

For one, Chromecast is getting something Google is calling the Remote Display API — essentially, apps can now use the TV as a secondary monitor to show off additional content.

This is being used by video games like Ubisoft’s “Speedboat Paradise” to project the race on TV while the phone becomes a touch-screen remote. And Autodesk’s Pixlr is using this technology to utilize the TV as a way to preview changes to a photo during the editing process while the editing tools are being accessible on the phone’s touch screen. It’s worth noting that this will be available to both Android and iOS apps, which means that Google’s casting technology is now more directly competing with Apple’s AirPlay.

Google is also making a cast-specific gaming API available to developers, which should allow them to build games that play out on multiple screens across Android and iOS devices as well as websites, and it has given developers the ability to queue videos within their apps as well.

This type of functionality was previously only available as part of the YouTube mobile app, which allows multiple users in the same room to build a kind of collaborative playlist with videos that are then being played consecutively. Now, any video publisher will be able to add similar features to their Chromecast-compatible app as well.