Kishores

Post Featured Icon: It allows to add font icons to post title, and there is option so that we can 
replace post thumbnail with font icon.
It supports:
<ul>
<li>dashicons</li>
<li>genericons</li>
<li>font-awesome</li>
</ul>
Please check here: <a href="http://opentuteplus.com/post-featured-font-icon/" rel="nofollow ugc">Demo 1</a> and <a href="http://blog.kishorechandra.co.in/project-fork-in-open-source/" rel="nofollow ugc">Demo 2</a>
It supports post,page.But we can add to custom post types to. It provides hooks i.e icon_post_type .
<blockquote>
Priority Support
If you are looking for more features, paid support or Custom WordPress Work, then you can hire me too. My email id : babunsahoo@gmail.com .
</blockquote>
<pre><code>// Our filter callback function
function icon_post_type_callback( $types ) {
 $types = array('post', 'page', 'product');
 return $types;
}
add_filter( 'icon_post_type', 'icon_post_type_callback', 10, 1 );
</code></pre>

Post Featured Font Icon

it supports dashicons, genericons, font-awesome.

sydcode

This plugin adds support for 18 free icon fonts (over 6000 icons).
<a href="https://developer.wordpress.org/resource/dashicons/" rel="nofollow ugc">Dashicons</a> (218 icons) 
<a href="http://www.elegantthemes.com/blog/resources/elegant-icon-font" rel="nofollow ugc">Elegant</a> (360 icons) 
<a href="http://elusiveicons.com/" rel="nofollow ugc">Elusive</a> (304 icons) 
<a href="https://github.com/danielbruce/entypo" rel="nofollow ugc">Entypo</a> (284 icons) 
<a href="http://fortawesome.github.io/Font-Awesome/" rel="nofollow ugc">Font Awesome</a> (519 icons) 
<a href="http://zurb.com/playground/foundation-icon-fonts-3" rel="nofollow ugc">Foundation</a> (284 icons) 
<a href="http://genericons.com/" rel="nofollow ugc">Genericons</a> (147 icons) 
<a href="https://icomoon.io/icons-icomoon.html" rel="nofollow ugc">IcoMoon Free</a> (491 icons) 
<a href="http://ionicons.com/" rel="nofollow ugc">Ionicons</a> (734 icnons) 
<a href="http://map-icons.com/" rel="nofollow ugc">Map Icons</a> (176 icons) 
<a href="http://materialdesignicons.com/" rel="nofollow ugc">Material Design</a> (1062 icons) 
<a href="http://mfglabs.github.io/mfglabs-iconset/" rel="nofollow ugc">MFG Labs</a> (186 icons) 
<a href="https://octicons.github.com/" rel="nofollow ugc">Octicons</a> (179 icons) 
<a href="https://useiconic.com/open/" rel="nofollow ugc">Open Iconic</a> (229 icons) 
<a href="http://pfefferle.github.io/openwebicons/" rel="nofollow ugc">OpenWeb</a> (118 icons) 
<a href="http://tenbytwenty.com/?xxxx_posts=sosa" rel="nofollow ugc">Sosa</a> (122 icons) 
<a href="http://themify.me/themify-icons" rel="nofollow ugc">Themify</a> (352 icons) 
<a href="http://typicons.com/" rel="nofollow ugc">Typicons</a> (336 icons)
Each font is freely distributed under an open source licence. 
Contact the author of a font if you have questions about using it.
Credits: 
<a href="http://jaicab.com/Sosa-Icon-Font-CSS/" rel="nofollow ugc">Jaime Caballero</a> for his Sosa stylesheet. 
<a href="https://gist.github.com/pnull/4510484" rel="nofollow ugc">pnull</a> for his Entypo stylesheet.

Icon Fonts

This plugin adds support for 18 free icon fonts (over 6000 icons).

Post Featured Font Icon vs Icon Fonts