Vine, the Twitter-owned video sharing app, now allows users to display their Twitter handle (@username) on their profile page and in videos messages. If you would like to take advantage of this new feature, you simply have to link your Twitter account to the Vine app.
How To Tie Your Twitter and Vine Accounts Together
Open the Vine app and go to the Profile tab. Tap on Settings and then scroll to the Social Networks > Twitter. Enter your username and password, and then tap on the small Tick icon to register your Twitter account.
Once done, head to the Settings > Account > Privacy and enable the Show my Twitter handle option:
Tap on Save to apply your new settings.
Moving forward, Vine will display your Twitter handle on your profile page and in your video messages (Vines):