Khanh

Fields is a WordPress plugin that let you manage write panels in your write/edit page. Fields supports post types that can have UIs.
With Fields, you can define boxes which appear in your write panels. A box can contain a number of groups which are sets of custom fields that you can define. Boxes are displayed as meta boxes and groups are shown as tabs that can be switched inside boxes. Within a group, fields can be shown as either textfields, textarea, drop boxes, radio group or check boxes.
Fields does not create custom post types, to do so, use other plugins such as WP Post Type UI.
Brief structure of Fields:
<ul>
<li>Fields can be: textfield, textarea, select (drop box), radio group and check boxes</li>
<li>A group contains fields</li>
<li>A box contains groups</li>
<li>You can choose which groups a box should include and which post types a box should appear in</li>
</ul>

Fields

Creates custom write panels to manage post custom fields.

Jeff Sherk

Adds 10 custom supplier fields to the General product data section of each product. Fields are Supplier Cost, Supplier Minimum Price, Supplier SKU, Supplier Description, Supplier Name, Supplier Address, Supplier Phone, Supplier Email, Supplier Location and Supplier Notes.

Supplier Data Fields for WooCommerce

this plugin is awesome ... needed these extra fields

awesome

Adds supplier fields to the product data section of each product.

Fields vs Supplier Data Fields for WooCommerce