This responsive PrestaShop module adds special popup to your website (you can define many popups with this feature) with feature to like page you will define on module configuration page. After like - customer will receive personal voucher code. Of course as a shop owner you can define voucher value. It is possible to do it with advanced voucher customization tool.
More informations about responsive popup coupon module is available on official module page here:
responsive facebook pop coupon module for prestashop
You can find there only valuable solutions for your e-commerce shop based on PrestaShop engine. Search the best plugin for your store that will meet your requirements and just use it.