remm

This plugin provide widget that display a list with categories and posts in your sidebar. 
Widget can save the opened categories, and use cache.

Wp Ajax Tree

This plugin provide a widget that display a category and pages tree on your sidebar, using ajax to collapse categories.

treenation

This integration will allow you to offer a tree each time a customer buys a product using WooCommerce. 
1 tree will be offered for each product purchase. For example, if a user makes 1 purchase which includes 2 x Product A and 3 x Product B, this user will receive an email with his 5 trees offered by your brand.
Some options are available: 
* Limit to some specific products: specify which products will trigger a tree planted, instead of all products. 
* Limit to 1 (or X) tree per order: a purchase of 5 products will only generate 1 tree.
Once you completed this integration, the system will be 100% automated.
Total integration takes less than 10 minutes on your side 🙂
General website: <a href="https://tree-nation.com/" title="Tree-Nation" rel="nofollow ugc">Tree-Nation</a> 
WooCommerce integration: <a href="https://tree-nation.com/auto-offer/" rel="nofollow ugc">Tree-Nation Auto-Offer</a>
<h3>Support</h3>
Contact us at auto-offer@tree-nation.com if you encounter any problem with this plugin.
<h3>External services</h3>
This plugin uses the Tree-Nation API to automate the process of offering trees for each product purchased through WooCommerce. 
For more information, please refer to our <a href="https://tree-nation.com/legal/terms-of-service" rel="nofollow ugc">Terms of Service</a> and <a href="https://tree-nation.com/legal/privacy-policy" rel="nofollow ugc">Privacy Policy</a>.

Tree-Nation for WooCommerce

This integration will allow you to offer a tree each time a customer buys a product using WooCommerce.

Wp Ajax Tree vs Tree-Nation for WooCommerce