themeszone

The plugin once activated will display a quantity field with increment / decrement buttons once add to cart button is pressed (e.g. the product is added to cart). 
Thus allowing customers to change the products number in the cart with out having to go to shopping cart 
page.
<a href="http://plugins.themes.zone" rel="nofollow ugc">PLUGIN DEMO</a> 
(click “Add to Cart button to see it in action”)
Feel free to ask any questions at <a href="https://themes.zone" rel="nofollow ugc">Themes Zone</a>

ThemesZone WooCommerce Ajax Quantity

ThemesZone WooCommerce Ajax Quantity Plugin shows quantity field on product listing once customer clicks "Add to Cart" button.

wooassist

This plugin displays the quantity field on the shop page of WooCommerce stores so customers can change the quantity before adding to cart.

Quantity Field on Shop Page for WooCommerce

This plugin displays the quantity field on the shop page of WooCommerce stores so customers can change the quantity before adding to cart.

ThemesZone WooCommerce Ajax Quantity vs Quantity Field on Shop Page for WooCommerce