DimitriAus

This lightweight plugin removes WordPress emoji functionality to reduce HTTP requests and improve page load times.
What it removes:
<ul>
<li>Emoji detection script from page head</li>
<li>Emoji styles from frontend and admin</li>
<li>TinyMCE wpemoji plugin</li>
<li>Emoji conversion in RSS feeds</li>
<li>Emoji handling in emails</li>
<li>DNS prefetch for emoji CDN</li>
</ul>

Manly No Emojis

Disables the emoji functionality in WordPress to improve performance.

leogg

This plugin will enable you to use the open source <a href="http://emojione.com/" rel="nofollow ugc">Emoji One</a> emoticons in your posts and pages. There are over 1100 emoticons for you to use.
Based on the <a href="https://wordpress.org/plugins/typepad-emoji-for-tinymce/" rel="ugc">TypePad emoji for TinyMCE</a> plugin by <a href="https://profiles.wordpress.org/picmo/" rel="nofollow ugc">picmo</a>. Emoji set designed and offered free by <a href="http://emojione.com/" rel="nofollow ugc">Emoji One</a>.

WP Emoji One

Add Emoji One emoticons to your posts and pages.

Manly No Emojis vs WP Emoji One