rammichael

From the Cloudflare Support website:
Q: Why do my server logs show Cloudflare’s IPs using Cloudflare?
A: When you sign on to Cloudflare the way your logs are displayed will change because Cloudflare 
 acts as a proxy. This means that your visitors are routed through the Cloudflare network. This 
 allows Cloudflare to stop attacks before they reach your network. It also allows Cloudflare to 
 speed up page load time by more efficiently routing packets and, more importantly, caching 
 static resources (images, javascript, css, etc.) on a very fast connection. However, as a 
 result, the connecting IP will always come from the Cloudflare network.
As a result, commenters’ IP will also be masked by Cloudflare. Luckily, Cloudflare sends the real 
user’s IP in a separate header. This plugin saves it, as well as the user’s geo-location (also 
provided by Cloudflare), and displays this information in the admin panel.
Note that when the blog is served directly to the internet (not through Cloudflare), anyone can 
spoof any IP address and geo-location by specifying any value in the request headers.

Real IP and Geo for Cloudflare

The plugin saves and displays visitors' real IP and location, instead of Cloudflare's.

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.

Real IP and Geo for Cloudflare vs Real IP Detector