51seven

This plugin adds a placeholder field into your Gravity Forms input and displays it as a proper HTML5 placeholder attribute without JavaScript (yaay!)
I took code from <a href="http://www.wpbeginner.com/wp-tutorials/how-to-add-placeholder-text-in-gravity-forms/" rel="nofollow ugc">this article from wpbeginner.com</a> and optimized it. Applause to them.

Placehold (Gravity Forms)

Adds a placeholder field to Gravity Forms

rkpolin

This is awesome placeholder plugins. This plugins automatically animate and back type writing effect your placeholder.
Compititable with all browser and contact form 7. But need to put placeholder before placeholder text in contact form 7. like [text text-948 placeholder “This is placeholder text”]
Features: 
1. Placeholder text fade backward. 
2. All browser support. 
3. Very lightweight plugins only 3KB. 
4. Contact form 7 supported.
You can see demo here <a href="http://facebond.com/plugins/rkp-awesome-placeholder/" rel="nofollow ugc">DEMO</a>
If you like this plugin please leave your ratings.
<h3>A brief Markdown Example</h3>
Ordered list:
<ol>
<li>Placeholder text fade backward.</li>
<li>All browser support.</li>
<li>Very lightweight plugins only 3KB.</li>
<li>Contact form 7 supported.</li>
</ol>

RKP Awesome Placeholder

This is awesome placeholder plugins. This plugins automatically animate and back type writing effect your placeholder.

Placehold (Gravity Forms) vs RKP Awesome Placeholder