Twitter introduced Vine, a new mobile service that lets you create and share beautiful, short looping videos. Like Tweets, the brevity of videos on Vine (6 seconds or less) inspires creativity.Vine is for free and available on the iPhone and iPod touch.
Vine - Features
• Unlimited uploads and free
• Instantly post videos on Vine, then share to Twitter and Facebook (more coming soon!)
• Find, follow, and interact with people close to you
• Explore trending posts, featured hashtags and editor's picks
Vine supports iPhone 3GS and higher and here is the download link. Vine.