Gravity Forms is N° 1 Form builder for WordPress
WordPress is a plattform thats growing for every year, and with this the amount of the plugins goes the same way. But if you gonna create a form of any kind, then there are actually only ONE plugin, Gravity Forms from Rocket Genius.
With Gravity form you can create forms in any way, with their form editor you add the different block with “drag n dropp”. There are lots of blocks, and each block have its own settings, and where its needed you have lots of pre-sorted CSS classes that easily can be added to change the layout of your form.
Some things cant be done in a practical way with a normal form builder, but with Gravity forms different add-ons can you easly do polls, survey, user registration, quiz and lots of other things. Last, but very importan, the documentation is fantastic and its tranlated to many, many language.
Gravity form can be purched in 3 licence, Personal, Business and Develope.