Facebook today released Poke, a standalone app for iPhone that allows users to use its famous Poke feature or send messages, photos or video to their friends for a designated period of time.

Messages expire after a specific time users set, either 1, 3, 5 or 10 seconds. After that, the content is removed from the app. This feature is similar to Snapchat, a popular mobile app that lets users communicate with photos and videos that disappear after being viewed. Also like Snapchat, users can add text and doodle on photos before they send them.

Users can send pokes and messages to one or multiple friends. They can also include their current location. Pokes and messages do not show up anywhere in Facebook’s desktop version or main mobile app. Poke also notifies users when the recipient tries to take a screenshot of the sender’s photo — another feature of Snapchat.

The fleeting nature of messages in Poke is a sharp contrast to the rest of Facebook’s product. Facebook Messenger saves users’ entire chat and message history in a single thread. Timeline makes it easy for anyone to look at someone’s past. Friendship pages show all of users’ interactions with another person. Poke is the opposite: content is meant to self-destruct. It’s for this reason that Snapchat has been maligned as an app for “sexting,” and Facebook will surely face similar critiques. The app does include an option to report or block users.

The “poke” is a feature that has been on Facebook since 2004. CEO Mark Zuckerberg once said of the poke, “We thought it would be fun to make a feature that has no specific purpose.”

But Poke the app definitely has a purpose, and that’s to appeal to younger users who are increasingly turning to Snapchat and other mobile apps to communicate in new, fun ways. Facebook, on the other hand, is something their parents and teachers use. The social network needs to continue to evolve its offering to be the dominant way people connect with their friends. The younger audience on Instagram was likely a large reason Facebook acquired the photo-sharing service.

Impressively, Poke was built in 12 days by a small team at Facebook. It’s this kind of speed that could help keep Facebook on the cusp of trends in mobile communication and maintain dominance across demographics.