The WooCommerce Express Shop Page plugin adds extra purchase options to the shop page without changing the layout of the page. We have intentionally not included add to cart checkboxes because adding these to the default shop page layout would result in a poor user experience. That's because the products are displayed in a grid layout quite spaced out, and it wouldn't be intuitive for customers to tick multiple products and add them to the cart at once.
Instead, we recommend our other plugin - WooCommerce Product Table - for showing add to cart checkboxes on the shop and category pages. This plugin actually changes the layout of your shop page, replacing it with a conversion-optimized order form view. The products are displayed in a structured table layout, with a 'Buy' column containing quantity fields, variations, and add to cart buttons.
With WooCommerce Product Table, you can display checkboxes either instead of or in addition to the add to cart buttons. That way, customers can tick multiple products and use a single 'Add selected to cart' button to add them all to their cart. This is much better for user experience than having add to cart checkboxes in the default shop page layout.
A shop page created using the WooCommerce Product Table plugin