boostetonwp

BTW Contact Forms is a plugin that lets you easily create and manage your contact forms (Customer support, quote requests, lead generation, recruitment, appointment scheduling, feedback and reviews, reporting or moderation, partnerships and collaborations, internal support (extranet / intranet)).
No complicated settings, no HTML or CSS code to manage. You simply choose the position and type of fields you want to include in your forms. 
That’s it! 
They then integrate seamlessly into your theme.
When your customers contact you, you receive an email and a message that can be viewed directly from your site’s administration panel. 
No risk of missing a message!
<h3>License</h3>
This plugin is licensed under the GPLv2 or later.

BTW Contact Forms

Create contact forms easily with automatic layout and no code required.

Dreb Bitanghol

This field will provide you more options and flexibility on how you would like to present an instruction or message to your client’s (or site in general) admin interface.
Features:
<ul>
<li>Support PHP.</li>
<li>Option to hide label when field is displayed.</li>
</ul>
Compatible with Advanced Custom Fields:
<ul>
<li>4 (tested up to 4.4.6)</li>
<li>5 (PRO, tested up to 5.3.7)</li>
</ul>
PS: You need <a href="https://wordpress.org/plugins/advanced-custom-fields/" rel="ugc">Advanced Custom Fields</a> installed to use this.
PPS: Even more awesome if you have <a href="http://www.advancedcustomfields.com/pro/" rel="nofollow ugc">Advanced Custom Fields PRO</a> installed.
Important note: Use this with utmost care.

ACF Enhanced Message Field

Exactly what I needed

Exactly what I needed. You could improve the plugin by making the textarea field look more like an IDE, with system fonts, syntax highlights and so on.

Perfect

Awesome!!

Adds an enhanced version of the default Message field to accept PHP and certainly no wpauto().

BTW Contact Forms vs ACF Enhanced Message Field