RelyWP

Elliot Sowersby / RelyWP

A simple plugin to allow your customers to apply coupons on product pages, and see the discounted price immediately.
All you need to do is install the plugin, and the apply coupon field will then appear on all your product pages.
When the customer enters a coupon code, it will automatically update the prices shown on the product pages, showing both the original price, and the sale price.

Apply Coupons on Product Pages – For WooCommerce

Allows customers to apply coupons on product pages and see the discounted price immediately.

gr8nilay

This plugin create a custom post type for coupon code that includes Coupon Start / End date, Discount in Percentage / Cash. The coupons are listed with all details so you can easily manage it from listing page. You can easily use this plugin by customization by your own to enable coupon feature to your site.
How to Use: 
This is custom post type so you can apply all the hooks / customization that you do with any custom post type. Below are the variables which are used to store values of coupons so you just need to use meta values for the same.
Coupon Code = np_ccode__ccode 
Discount In ( % or $ ) = np_ccode__discount_in 
Discount Amount/Percent = np_ccode__amt_per 
Coupon Start Date = np_ccode__ccstart_date 
Coupon End Date = np_ccode__ccstart_date
You can use above meta keys into your site by your own to customize your site coupon feature.

Easy Coupon Code WP

Nice..!!

Provides you the custom post type with ready meta fields to enable coupon module to your site.

Apply Coupons on Product Pages – For WooCommerce vs Easy Coupon Code WP