wooassist

This plugin adds a custom field in the checkout page to ask your customers where they heard about your store.
This plugin also offers an “Other” field where your customer can provide a specific answer in a separate textbox.
Features:
<ul>
<li>Easily change the labels and choices for the custom field in the checkout page.</li>
<li>View reports on the “Reports” section in WooCommerce.</li>
<li>Enable/disable the custom field to be required on checkout.</li>
<li>Enable/disable the “Other” field.</li>
<li>Modify order statuses you want to include in the reports.</li>
<li>Export Orders with Customer Source field</li>
</ul>

Where Did You Hear About Us Checkout Field for WooCommerce

Adds a custom field in the checkout page to ask your customers where they've heard about your store.

Automattic

WooCommerce

WooThemes

James Koster

Tiago Noronha

A simple plugin that adds an attractive sharing component to product pages. Prompt visitors to share your products on Facebook, Twitter, Pinterest or via Email.
This plugin requires the Storefront theme and WooCommerce plugin to be installed.

Storefront Product Sharing

Add attractive social sharing icons for Facebook, Twitter, Pinterest and Email to your product pages.

Where Did You Hear About Us Checkout Field for WooCommerce vs Storefront Product Sharing