Changelog

Improved display for variable products that have promo free shipping enabled;
Customization options for promo free shipping product message banner: option to set text color, background color and border color;
Additional row in WooCommerce’s dashboard stats widget, that shows total number of orders that had promotional free shipping;
Improved display for orders that have promotional free shipping (coupon is highlighted and there’s a new order totals row indicating promotional free shipping applies);
Improved filtering of free shipping methods on checkout;
Improved syncing of cart contents and promotional free shipping status.

Coupon editing and removal is now restricted for the coupon managed by this plugin
Coupon managed by this plugin is now explicitly marked in coupon listing
Shipping class editing is now restricted for the shipping class managed by this plugin
Shipping class managed by this plugin is now explicitly marked in shipping class listing
Added link to plugin configuration page to the corresponding plugin listing row
Added option to, on checkout, if free shipping is available, hide paid shipping methods

Improved handling of variable products
Added filter and action hooks extension points
Added option to disable product-page promotional message banner
Added column in product listing page to show whether a product grants free shipping or not
Added filter in product listing page to allow selecting only products that grant free shipping
Added quick actions in product listing page for enabling/disabling free shipping for a given product
Improved assets install/uninstall sequence