V2 simply must have the ability to make a video hands-free, without having to press on the screen. That Vine 1 didn’t have this ability was a huge oversight. Instead we had to jump through some hoops using iPhone accessibility tools to accomplish hands-free recording, but it was very kludgey. It also makes it more difficult for individuals to make better videos, while those with large followings had other people doing all the video recording for them.
The Photo Booth app that comes with Apple computers is a good model. When you tap the record button, there is a countdown on the screen (flashing large numbers) before it starts recording so you can get into place. The ability to set the number of seconds for the countdown would be fantastic. Sometimes you can get into place faster than others.
PLEASE, @dom, add this to V2, thank you!