Today, a bunch of app developers showed off their latest AR apps for Google’s augmented reality platform, but Google didn’t stay too still either.

The team at Google released what could be one of its simplest apps ever. It’s called an “experiment,” and with good reason — it’s literally just an app for drawing white lines. “Just a line,” takes the baton from the company’s Tilt Brush virtual reality painting app and strips away every custom tool and setting, leaving you with the ability to annotate the world with digital white lines suspended in space and anchored to reality.

The big difference is a lot more people have ARCore-compatible phones than have VR headsets, so this is going to be a cool first experience with “3D painting” for a lot of people.

Users hold up their phones and use their fingers to draw lines; the interface relies on a ton of physical movement, using the phone itself as the main controller. Users can record videos of their creations and download them after if they want to look at all the pretty lines they made.

You’ll need an ARCore-compatible phone to try out the app; you’ll also probably need to manage your expectations for what you’re getting. You can just make lines! That is it.

Download it here.