Rishi Mehta

This plugin activate add to cart through ajax on varible product. By default woocommerce is not having this feature. Plugin is adding own jquery which is differ from woocommerce default add to cart jquery for simple product.
This plugin also supports sending additional field and other data added by other plugins. It will work with most of product addon and extra field data.
Let me know if you stumble upon any plugin conflict in support forum.

Woocommerce Ajax add to cart for variable products

This plugin activate add to cart through ajax on varible product.

danyn

This plugin extends WooCommerce Layered Nav Widget in three important ways 
*It shows a given layered nav only on the product categories you declare 
*It makes the entire layered nav button area clickable including the checkbox 
*It adds information from the Layered Nav Widget onto the links of variable products in order to save the user a few click once they land on the variable product page.

Birch Layered Nav

This plugin extends WooCommerce Layered Nav Widget. As such the latest stable release of WooCommerce is a dependancy. It Still Allows the user to refi …

Woocommerce Ajax add to cart for variable products vs Birch Layered Nav