[FormBuilder] - Add a Twitter SMS notification

[loopion]

Hi,

I did a Twitter SMS notification for Wordpress (http://blog.loopion.com/comment-twitter-sms-notification/), so I would like to do the same in CMS Made Simple but with FormBuilder to have a SMS when somebody submit a new form.

I need to know :

How to add a new feature in the drop down "Fast field adder" or "Add New Field" ? Where can I found more information and more documentation ? Do somebody have an idea where I can implement code ?

Thx