We have also written a detailed review of this plugin and there is no match for Formidable Pro. It is a unique type of WordPress addon that makes it easy to manage user submitted data via WordPress backend or frontend. It is the best available form builder plugin comes with tons of features expected by no one at an affordable price.
Formidable Pro is much more than a form builder and we have covered a detailed post on it.
If you need a plugin to build forms quickly and easily, you may go for Gravity forms. It is a valuable tool to generate attractive and advanced forms within minutes. This plugin offers drag and drop form builder and saves form entries in database. Loads of addons are available for Gravity Forms both from official developer and from 3rd party developers. The only thing that may annoy you is its pretty high price in comparison with other form plugins. Gravity Forms have PayPal addon with which you can get paid by online applicants at submission.
This form builder builds forms with awesome styles. It is a cheap plugin comes with tons of features along with database from entry management, advanced styling,advanced field options and more. We highly recommend you this plugin if you need not PayPal payment option to collect payment online after registration. ( because this plugin does not have PayPal payment feature )
It is the cheapest form plugin with which online registrations can be collected. This plugin allows all tools to create a registration form and it is a robust form builder, too. But you can not collect online payment with this plugin because it lacks PayPal payment option.