Vine - available to download now for iOS devices from the Apple App Store - allows users to create and post six-second videos, and then share them on Twitter and other social networks.
Twitter chief executive Dick Costolo posted the first embedded Vine video on Twitter yesterday (January 23), which features him making a steak tartare.
Just as Twitter limits users to text posts of just 140 characters, Vine limits posters to videos of no more than six seconds.
Users can also post Vine videos on Facebook, and support for more social networks is "coming soon", Vine said.
Twitter purchased the Vine Labs startup last October. In a blurb on its website, Vine says it offers the "best way to see and share life in motion. Create beautiful looping videos in a fun way, then share with your friends and family."
Vine clearly hopes that it will be able to do for video what Instagram has done for photos - create an accessible and visually appealing way to quickly share images with other users, in this case moving ones.
The app works by users hitting record on the app and then putting their thumb on the screen to start filming. Taking the thumb away stops the process.
Users can do one straight take, or lots of little shots and then stitch them together, such as in Costolo's video. They can also follow other Vine users and search for clips to watch.
Dom Hofmann, co-founder and GM of Vine, said: "They're little windows into the people, settings, ideas and objects that make up your life. They're quirky, and we think that's part of what makes them so special."
Vine will be initially only be available to iPad, iPhone and iPod Touch users, but it is expected that an Android version of the app will follow shortly.
Update: Vine Labs has already released Version 1.0.2 of the iOS app after fixing "a few launch day hiccups".