Functionality
Gravity forms has a very intutive drag and drop form builder in its backend.
There is a list of input types on the right hand side which you can drag and drop it on the left to create your form.

In the dashboard, you can manage all your forms and quickly disable/enable them via a toggle.

One thing I like about the plugin is that overall it follows the style conventions of WordPress instead of creating its own custom style in the backend like Yoast.
The crazy thing about Gravity forms is that you can install plugins(Called Add-Ons) specific for Gravity forms from the sidebar itself. Most of these plugins enable forms to be automatically submitted to a CRM software of your choice. Take a look at the Add-Ons(They can be fairly pricey)