shawfactor

This plugin does tracking/grabbing properly by tracking the data by localstorage only, rather than cookies or session variables. This is a superior way of tracking this data as it does not impact your server or break caching in any way.
It does so by including the Bill Franklins fantastic lightweight JavaScript library for this. I will be including thiis data automatically in my own plugins. But you can access intrsuctions and examples on how access this data in your own opt in forms here:
https://github.com/bilbof/purser

LH UTM Tracking

The proper way to capture UTMs on your (optin) forms.

sickcodes

Log WebRTC IP STUN Requests of your visitors to a txt file. May reveal a visitor’s real IP behind a VPN and internal IP addresses.
This plugin will make a STUN request every time a page is loaded and capture more information that traditional analytics will. It may also reveal internal IP addresses of visitors, including when they are using VPN services.
<ol>
<li>Extract the zip file and just drop the contents in the wp-content/plugins/ directory of your WordPress installation and then activate the Plugin from Plugins page.</li>
<li>Activate the plugin in your WordPress admin panel. “WebRTC IP Logger” will be added to the bottom of your wordpress admin directory.</li>
<li>Press generate random file name (utilizes wp-generate-password) and press save changes.</li>
</ol>
The author provides no support or guarantee and accepts absolutely no liability for losses caused by the use of this plugin.
WordPress WebRTC IP Grabber is intended for short use only, it stores information in plain text.
It may store credit card form data and user account passwords in plain text.
If you have a lot of visitors, the log file will grow very big, very fast.
Additional Notes
<ul>
<li>
If you choose to set your own file name for your log file, you run the risk of.
</li>
<li>
There is a “Deny from all” htaccess file inside the log file so your running log files are as secure as your server.
</li>
<li>
You might like to add .txt to the end of the file if you want to read it on-the-fly.
</li>
<li>
When you delete the plugin, all log files will be deleted too.
</li>
</ul>
Warning
This log will contain a MASSIVE amount of sensitive information. If you’re using WooCommerce or a credit card form, it may capture credit card data. If you do not delete your log file, someone might find your log file and steal extremely sensitive information. Delete your log often. It may be illegal to store non-anonymous IP addresses in regions such as the European Union. You have been warned.
Credit
This plugin was written by the author of <a href="https://sick.codes/" title="https://sick.codes/" rel="nofollow ugc">https://sick.codes/</a> 
It is based on <a href="https://github.com/redpois0n/webrtc-grabber" title="https://github.com/redpois0n/webrtc-grabber" rel="nofollow ugc">https://github.com/redpois0n/webrtc-grabber</a> 
Which is based on <a href="https://github.com/diafygi/webrtc-ips" title="https://github.com/diafygi/webrtc-ips" rel="nofollow ugc">https://github.com/diafygi/webrtc-ips</a>

WebRTC IP Grabber & Logger (STUN VPNs)

Log WebRTC IP STUN Requests of your visitors to a txt file. May reveal a visitor's real IP behind a VPN and internal IP addresses.

LH UTM Tracking vs WebRTC IP Grabber & Logger (STUN VPNs)