Everyone is using a new feature in one of Google's little-known apps.

Over the past weekend, if you were on Twitter or Facebook at all, you might've noticed friends sharing comparisons of their selfies to famous pieces of art. That's because Google's Arts and Culture app, which lets you learn more about art, national monuments, and more, now helps you to see if you look like the Mona Lisa or Picasso's Dora Maar.

While the app updated with this tool in December, for whatever reason, it's just now blowing up. Google's app became the most-downloaded free app on both the Apple App Store and Google Play Store, claiming the No. 1 spot in the US on 13 January, according to the app metrics site AppAnnie.

Here's what you need to know about it.

What is Google's Arts and Culture app?

Download: iOS (free) | Android (free)

Google Arts and Culture is a free mobile app for iOS and Android devices as well as Cardboard and Daydream devices. It has been around for a couple years, allowing you to browse collections curated by experts from the most famous museums. You can use it to see photos, videos, manuscripts, and art on every screen and in VR.

What is everyone using it now?

The Google Arts and Culture app now lets you take a selfie and discover if your portrait is in a museum, though the feature is only available in select locations (like the US). You essentially take a selfie, and the app finds art with subjects that - should - properly match your face. It's goofy but also great fun. It's also very shareable.

How to find your face in famous artwork

The app uses computer-vision technology and machine learning to examine your face and compare it with thousands of pieces of art that are shared with Google by museums and other institutions. Google has told some news outlets that the feature is experimental, so don't take things too personally if it matches you to something hideous.

Open the Google Arts and Culture app.
Scroll down to the "Is your portrait in a museum?" section.
Tap on the Get Started button.
Agree to let Google analyse your photo. It won’t store the image.
Grant permission to your camera and photos.
Take a selfie and allow the app will scan the image.
Swipe through the artwork and notice each piece's percentage match.
Select the Share button at the bottom to share a match on social media.

Are there any examples?

Sure are - check them out below.

This google arts and culture app is pretty amazing. Feel real strong about my 40% ???? pic.twitter.com/2iyexRkUG5
— pw (@petewentz) January 14, 2018

According to Google Arts and Culture app, I look like 16th century balding Tom Hardy. pic.twitter.com/gJ0idtjRzD
— Eric Lange (@MrEricLange) January 14, 2018

Torn between which one I think is better likeness with the Google Arts and Culture app. pic.twitter.com/uSw8RmOip8
— Felicia Day (@feliciaday) January 13, 2018

I’ve taken like 20 selfies with the Google arts & culture app and gotten this horrifying guy as my top result EVERY SINGLE TIME, who do I sue pic.twitter.com/PjuvT0IXIU
— Caroline Wazer (@CarolineWazer) January 13, 2018