The new Facebook Moments app.
This one is a photo-sharing app called Moments, and the concept is pretty simple.
When you first launch Moments, the app pulls in photos from your camera roll. It then uses the same facial recognition technology Facebook's website has to identify your friends in those photos. You then have the option to send the batch of those photos to those people.
Facebook gets all the information about you and your friends from your Facebook account. You can log in the old-fashioned way, or use Facebook's integration with Android or iPhone. If you try to send photos to someone who doesn't have the new Moments app, that person will get a message in the Facebook Messenger app prompting them to download Moments.
And that's it! The idea is to have an easy way to share big groups of photos with the people in them without having to email or text them one by one.
Facebook Creative labs has launched several social networking apps over the last two years or so. None of them have been massive hits, and a lot of them borrowed heavily from features found in other apps.
Facebook will tell you it's not trying to create the next social networking phenomenon with Creative Labs apps (although it certainly wouldn't mind stumbling on to something like that), but instead uses the apps to test features for the main Facebook app.
For example, some navigation features in Paper, the company's news app, can be found in Instant Articles, the native publishing platform partners like The New York Times and BuzzFeed have used to post stories directly to Facebook.
Moments will be available on iPhone and Android on Monday.