pipdig

Use the power of the cloud and a global CDN to restrict access to your login page.
CloudGuard brings global and cloud driven protection to your login page. Using Cloudflare’s free Geolocation service, this super lightweight plugin restricts access to your login page, allowing access to only your chosen countries. This means that any login attempts from the rest of the world will be automatically blocked.
Additionally, this plugin tracks any unauthorized login attempts and displays them on a <a href="https://wordpress.org/plugins/cloudguard/screenshots/" rel="ugc">world map</a> in your dashboard.
<h3>Main Features</h3>
<ul>
<li>Protect your login page globally.</li>
<li>Reduce server load.</li>
<li>Country based IP ranges constantly updated by Cloudflare.</li>
<li>Monitor login attempts via your dashboard.</li>
<li>Block access to the login page or redirect to a URL.</li>
</ul>
<h3>Why Cloudflare’s Geolocation?</h3>
There are other plugins which can restrict your login page by geographic location. However, these plugins use your server to detect the IP and compare this to a geographic location. This adds extra overhead to your site, takes up space on your server, and requires frequent updates to keep the IP list relevant.
CloudGuard is different. Since we leverage Cloudflare’s geolocation service, your server simply has to read the data, rather than compute and store it locally. Cloudflare does the grunt work, leaving your site safe, secure and optimized.
Note: This plugin requires that you have an account (including the free option) on <a href="https://www.cloudflare.com" rel="nofollow ugc">Cloudflare</a> with <a href="https://support.cloudflare.com/hc/en-us/articles/200168236-What-does-Cloudflare-IP-Geolocation-do-" rel="nofollow ugc">Geolocation</a> enabled.
This free plugin is brought to you by <a href="https://www.pipdig.co/" rel="nofollow ugc">pipdig</a>
Please consider <a href="https://wordpress.org/support/view/plugin-reviews/cloudguard?rate=5#postform" rel="ugc">leaving a 5-star rating</a> if this plugin has helped you.

CloudGuard

I consider it essential. You can do the same thing with Firewall Rules in Cloudflare this is highly visible in Wordpress' dashboard unlike Cloudflare's stats.

Love this plugin

Use Cloudflare's free geolocation service to restrict access to your site's login page.

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.

CloudGuard vs Real IP Detector