Facebook has pulled the plug on its experimental Creative Labs, which produced standalone apps like Rooms, Riff, and Slingshot. 

As first noted by CNET, all three apps are no longer available, while the group's Facebook Page is also offline.

If you're struggling to recall just what these apps did, that might give you a clue as to why they've been discontinued.

The Snapchat-like Slingshot arrived last year. It let users send messages that eventually self-destructed, but in a bid to distinguish itself from Snapchat, recipients could not view the sender's content until they sent a message in return. In PCMag's review, we found that it was a "cleverly designed ephemeral photo and video swapping app [that fell] short of Snapchat's mark."

That was followed by Rooms, a 90s chat room throwback that allowed users to chat anonymously about topics that interested them. Unfortunatley, we concluded, "Rooms is the Facebook-esque chatroom app for 21st century that no one is asking for."

Facebook Riff, which arrived in April, allowed users to collaborate and add on to a friend's video. We praised its simplicity and suggested its connection to Facebook would help distinguish itself from a sea of similar apps.

Facebook did not immediately respond to a request for comment, but told Re/code that standalone apps are not completely off the table. They just won't be produced under the Creative Labs umbrella.