wojciechborowicz

This plugin will let you add Google Ads conversion codes given by Google. 
This includes adding scripts in the head section of your website, to display them on specific pages, checkout or contact form (contact form 7)

Conversion Helper

This plugin will let you add Google Ads conversion codes given by Google.

asanabria11

Add Adwords, Facebook pixel or any Conversion Tracking scripts using variables like product ID, post id, title or custom ones.
This plugin lets you insert any marketing script anywhere you want, before the head element closes, after the body or even before the body tag closes.
Also you can use custom variables to share between scripts like conversion id or Facebook pixel id. as well as dynamic ones like product id.
Also you can set your scripts to show in specific pages or events like right when somebody completes an order or when they are in a product page in case you are using Woocomerce.
<blockquote>
Premium version 
 With the premium version you have no limits in variables or scripts and you get much more options, you can check out here if you want more power to your marketing scripts: 
 <a href="http://www.ultimateconversiontrackingcode.com/" rel="nofollow ugc">http://www.ultimateconversiontrackingcode.com/</a>
</blockquote>

Ultimate Conversion Tracking Code

Add Adwords, Facebook pixel or any Conversion Tracking scripts using variables like product ID, post id, title or custom ones.

Conversion Helper vs Ultimate Conversion Tracking Code