Functionality
Ninja forms has a easy 5 minute setup process in the backend. When you install the plugin, it automatically creates a contact form for you (assuming it’s widely used).
Creating your own form is as easy as clicking the add new button.

You are then presented to pick from a couple of read made templates which you could tweak or you can create your custom form with a blank form template

You are then taken to a screen with a draggable fields panel on your right and your form on the left. You can add and customize a number of fields that are provided for you.
Over here, as you can see Ninja forms visually takes over the WordPress dashboard. Their design isn’t bad but why unnecessarily take away control of the dashboard from the users?

The one thing I like about the plugin is that it’s very easy to setup. If you are looking to create a contact form then it already does it for you. Styling the forms can be tricky to navigate around but settings such as required field, placeholder, and label name can be made using the form setup on the right.
By default, your form submissions are stored in your WordPress database for easy access through your WordPress Dashboard under Ninja Forms -> Submissions, and are also sent to the email address associated with your WordPress user account.