Markus Echterhoff

This plugin provides a library of extended functionality for Bogo. My Bogo based translation plugins depend on it.
If you are developing a plugin and wish to make it compatible to Bogo, you may find some convenient API calls in here.
It also contains an email localization implementation that can localize emails depending on the user who receives them.
For example usages see <a href="https://wordpress.org/plugins/bogo-bbpress/" rel="ugc">Bogo BBPress</a> or <a href="https://wordpress.org/plugins/bogo-buddypress/" rel="ugc">Bogo BuddyPress</a>.

BogoXLib

Bogo extension library to create multilingual plugins or plugins that make other plugins multilingual.

pimwick

Offer “Buy One, Get One Free” deals for your customers in a single step! 
Activating BOGO Free deals in your WooCommerce store has never been easier. Simply name your BOGO deal and click Publish. That’s it!
<blockquote>
The <a href="https://pimwick.com/pw-bogo" rel="nofollow ugc">Pro version</a> includes even more great features:
<ul>
<li>Buy X, Get X – For example, “Buy 3, Get 2 Free!”</li>
<li>% Off – For example, “Buy One, Get One 75% Off”</li>
<li>Spend X, Get X – For example, “Free Product with purchase of $25 or more”</li>
<li>Automatically add the discounted products to the customer’s cart</li>
<li>Optionally require a coupon to activate the BOGO</li>
<li>Limit the number of times the BOGO deal can be applied per order</li>
<li>Specify that only identical products or variations are discounted</li>
<li>Schedule begin and end dates for the promotions</li>
<li>Specify products by category</li>
<li>Include or exclude individual products</li>
<li>Eligible products can be different than the Discounted products</li>
<li>Options to exclude sale items or not allow other coupons in conjunction with BOGO offer</li>
<li>Compatible with all major payment gateways such as PayPal and Klarna.</li>
<li><a href="https://pimwick.com/pw-bogo" rel="nofollow ugc">Get these amazing features and more!</a></li>
</ul>
</blockquote>
Easy to end the promotion 
Simply open the BOGO deal and click Move to Trash.
Your time is priceless 
There are plugins that can be configured to offer BOGO Free deals but they are difficult to set up and require a lot of trial and error. If you’re looking for a straightforward BOGO Free promotion, this plugin is the way to go.
PW WooCommerce BOGO takes the guesswork out of offering Buy One, Get One deals. It’s so easy to use!

PW WooCommerce BOGO

as the title suggests, the plugin adds bogo for all products on the website.

Basically any product that is added to the cart, when a 2nd one is added the bogo is applied, no other controls, you can't limit the bogo to 1 product/category/discount item

plugin adds a bogo for all website products, no other options

PW WooCommerce BOGO Free makes Buy One, Get One promotions so easy!

BogoXLib vs PW WooCommerce BOGO