WooCommerce is super easy to use and helps you bring your store online fast. Thanks to the WooCommerce Flash Sale Countdown Plugin, you can build more interest in your store. You simply have to add products and categories to flash sales and the rest is easy.
WooCommerce Flash Sale Countdown should work with most themes. Your visitors will be able to see your sales events end and how many quantities are available at a discounted price.
You can select product elements to show, widget settings, position, and other factors in the back-end. This is a paid script from Template Monster.