Masoud Binaei

This plugin allow WordPress to detect Real visitors IP Address when WordPress is behind of Reverse Proxy, Load Balancer or CDN. 
It will start working as soon as you activate it.
It is also compatible:
<ul>
<li>Cloudflare.com</li>
<li>geniusguard.com</li>
<li>central-hosting.com</li>
<li>incapsula.com</li>
<li>sucuri.net</li>
<li>barracuda.com</li>
<li>f5.com And Other…</li>
</ul>

Real IP Detector

Very good

This plugin allow WordPress to detect Real visitors IP Address.

This plugin can detect information such as country name, web browser and operating system from your commenters and then displays them on your comment section or anywhere you like.
Features:
<ul>
<li>
Detects and shows commenter?s country flag, web browser and operating system automatically
</li>
<li>
Supports many web browsers and operating systems: major desktop browsers, antiquated browsers, blogging software (for trackbacks and pingbacks), text based browsers, various PDAs and cell phones.
</li>
<li>
Uses a binay file for IP to country resolution and supports database sources from Webhosting.info – Software77.net
</li>
<li>
The returned string can be configed as a template to suite your theme
</li>
</ul>
<h3>Credits</h3>
Especially thanks to
<ul>
<li>
<a href="http://priyadi.net/" title="Priyadi Iman Nurcahyo" rel="nofollow ugc">Priyadi Iman Nurcahyo</a> for his <a href="http://priyadi.net/archives/2005/03/29/wordpress-browser-detection-plugin/" title="WordPress Browser Detection Plugin" rel="nofollow ugc">WordPress Browser Detection Plugin</a>
</li>
<li>
<a href="http://firestats.cc/" title="Omry Yadan" rel="nofollow ugc">Omry Yadan</a> for his <a href="http://firestats.cc/wiki/EasyIP2Country" title="Easy IP2Country" rel="nofollow ugc">Easy IP2Country </a> plugin
</li>
</ul>

Comment Info Detector

Enables you to detect your commenter's info and show their country flag, web browser, operating system automatically.

Real IP Detector vs Comment Info Detector