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Gravity Form Square plugin is a WordPress plugin that allows users to pay from their gravity form using Square payment gateway. 
This will help you to add Square payment option to your form created through Gravity Form plugin. So users will be able to pay via Credit Card number 
and this payment will process through your Square account.
<h3>Features</h3>
Easy to setup. 
Admin can authorize his account by one click. . 
Get payment instantly.

Gravity Forms Square (Free)

Gravity Form Square plugin is a WordPress plugin that allows users to pay from their gravity form using Square payment gateway.

Mike Mamaril

Connect to your Square API and filter Payments made and import them into WooCommerce as new orders. This uses 
the official V1 and V2 Square SDK and requires you to create an application to grant access.

S2W Payments

Search fulfilled payments from Square and import them to WooCommerce as orders by matching product SKU's on both Square and WooCommerce.

Gravity Forms Square (Free) vs S2W Payments