WEAM Product Manager for WooCommerce has a Free version, sufficient for many small webshops.
For webshops with more requirements the Pro version will be good to go.
Here is a quick comparison

ProductManager Free
+ product Editor Basic
+ Product Attributes Basic
+ Product Health Basic
+ Settings Basic

Product Manager Pro
+ product Editor Pro
+ Product Attributes Pro
+ Product Health Pro
+ Product Pricing Pro
+ Store Audit Pro
+ Settings Pro

Check our Features for detailed comparison.
And feel free to check out our LIVE DEMO of the Pro version (see homepage)