There were more than 25 million installs of Google Cardboard apps from Google Play between June 2014 and December 2015, 10 million of which took place in the last quarter of 2015, the company announced in a blog post.

The top app for Cardboard, Google’s virtual reality (VR) device, based on installs, user ratings and reviews, was Chair In A Room, which “uses the power of Google Cardboard to create a dark adventure”, followed by storytelling app Vrse.

VR3

These were followed by Lamper VR: Firefly Rescue, Caaaaard-board and Proton Plus to round up the top five.

What’s more, 350,000 hours of YouTube videos were watched in VR thanks to Cardboard.

“With just Cardboard and the smartphone in your pocket, you can travel to faraway places and visit imagined worlds… everyone from droid lovers and Sunday edition subscribers, to big kids and grandmas have been able to enjoy VR — often for the very first time,” the company said in a blog post.

Earlier this month, the company formed a VR unit and chose Clay Bavor, one of Cardboard’s founders, as its head, a sign it wants to take on rivals such as Facebook which have made the running on VR.

Last year, The New York Times created a VR app that supported playback for Cardboard and distributed around one million Cardboard viewers to its subscribers.

The Cardboard team also introduced an integration with GoPro that brings VR video to YouTube.