As we noted a few weeks ago, Facebook is currently in the process of developing a new Snapchat-like chat service separate from its main Messenger/Facebook inbox offering, even though it just recently removed its Poke app from the App Store.

Today Facebook “accidentally” published an early version of the upcoming software, called Slingshot, to the iOS App Store in a few countries. The app allows users to share a photo (or video) with friends, but those friends are unable to view the photo until they respond with a photo of their own. A “react” button allows recipients to quickly snap their reaction to an incoming message and send it back as a response.

As noted above however, Facebook says the rollout was an accident, and the app was quickly pulled from sale in all markets where it was available. Facebook hasn’t yet given a time table for the app’s real roll out, but said it is coming “soon.”