Ren Ventura

Simply install the plugin and add the appropraite CSS class to the form field you want to assign an attribute. This is done within the Form Editor under the Advanced tab of the field. The classes are “disabled” for the disabled attribute and “readonly” for the readonly attribute (don’t include the quotation marks).

Disable Gravity Forms Fields

This is a simple plugin that lets Gravity Forms users set a form field's attribute to either disabled or readonly.

WebHolism

When activated this plugin allows Gravity Forms elements to be split into columns. To implement the columns three new elements (Row Start, Column Break, and Row End) which are introduced into the Gravity Forms administration area in a group labelled as Multiple Columns Fields.
For each form, in its form settings it is possible to enable and disable the plugin’s CSS and JS that are used by the plugin. The CSS file is responsible for the layout of the form, and the JS file is used to remove unwanted spacing generated if using conditional logic to hide form elements. It is advised to keep the CSS enabled at all times, but the JS should only be enabled in the case of hidden elements through the use of conditional logic.
** Note: Plugin no longer supports initial column specification using Sections in versions 2 and before. If updating plugin from a version prior to version 3, the form will need to be recreated with the current design definitions.**
Note: If updating from version 3.0.3 or earlier. If the columns are not displaying as expected, first please visit the Form Settings for each form and check the Enable CSS checkbox.
Support this plugin by purchasing <a href="https://rocketgenius.pxf.io/multicolumns" rel="nofollow ugc">Gravity Forms</a> now, using the affiliate link. No extra cost to you, and a big help towards supporting this plugin.
<h3>Credits</h3>
A big thank you goes to K. Woodberry, T. Kaufenberg, J. Wright, D. Donnelly, A. Sharma, L. Hanbury-Pickett for identifying issues, and assisting in finding solutions to them. 🙂

Multiple Columns for Gravity Forms

Gravity form is good but its lacking lots of functionality for layout creation. This plugin give multi column function to create within form. Doing exactly what it says. Just install and add columns. That's it. One suggestion though, if you can add css box to add css class to column, that will be great. 

Nice Plugin for simple functionality

Introduces new form elements into Gravity Forms which allow for simple column creation.

Disable Gravity Forms Fields vs Multiple Columns for Gravity Forms