Akeda Bagus

This plugin is an extension to <a href="https://wordpress.org/plugins/slack" rel="ugc">Slack plugin</a> that allows you to send notifications to Slack channels whenever payment in WooCommerce is marked as complete.
The new event will be shown on integration setting with text When a payment in WooCommerce is marked as complete. If checked then notification will be delivered once payment is marked as complete.
You can alter the message with <code>slack_woocommerce_order_status_completed_message</code> filter. The filter receives following parameters (ordered by position):
<ul>
<li><code>$message</code> — Default string of message to be delivered</li>
<li><code>$order</code> — Order object</li>
</ul>
Development of this plugin is done on <a href="https://github.com/gedex/wp-slack-woocommerce" rel="nofollow ugc">GitHub</a>. Pull requests are always welcome.

Slack WooCommerce

Send notifications to Slack channels whenever payment in WooCommerce is marked as complete.

braveryk7

Send Chat Tools is a plugin that allows you to send WordPress announcements to chat tools. 
Currently, it sends an announcement when a comment is received. 
You can instantly check comments that you didn’t notice with the default email notification.

Send Chat Tools

Send Chat Tools is a plugin that allows you to send WordPress announcements to chat tools.

Slack WooCommerce vs Send Chat Tools