Video demonstrating the Vi: http://youtu.be/YYnH5ZjXKYs
If you want to use them the vi and a dependency can be grabbed here:
https://docs.google.com/file/d/0B4fOsi0gJv2fQ2F4bXBmZi1VVGc/edit https://docs.google.com/file/d/0B4fOsi0gJv2fb3JkZ1BwVmQyaFE/edit