When Vine, the video-sharing app, made its debut earlier this year, there was skepticism as to how it would be embraced. But the app, which allows users to upload six-second clips (think Twitter meets YouTube), caught on quickly and has become a popular social media tool amongst app addicts and celebs alike. From Wiz Khalifa and Lucy Hale to RiFF RAFF and Tyra Banks, here are 20 celebrities you should follow on Vine.