Sean Davis

Built for use with the Easy Digital Downloads plugin, this extension displays a Clear Cart link in the checkout cart and allows you to remove all items from the shopping cart with a single click. You can also choose a page to redirect to once the cart is cleared.
Follow EDD Clear Cart’s development on <a href="https://github.com/sdavismedia/edd-clear-cart" rel="nofollow ugc">Github</a>.

Easy Digital Downloads – Clear Cart

Adds a Clear Cart link to the Easy Digital Downloads checkout cart.

Andrew Norcross

Liquid Web

Set a time limit on a customer checking out. Include a “time to check out” 
countdown to encourage your customers to complete their purchase.
Features
<ul>
<li>CSS based countdown display</li>
<li>available actions and filters to modify functionality.</li>
</ul>

WooCommerce Cart Expiration

Set a time limit on a customer checking out.

Easy Digital Downloads – Clear Cart vs WooCommerce Cart Expiration