schnack can send a message to a Slack channel when a new comment is awaiting for approval. In order to configure this service just create a slack webhook and paste its URL to notify.slack.webhook_url in schnack.json.
Add a plugins.notify-slack section to your Schnack config file schnack.json:
{
"plugins": {
"notify-slack": {
"webhook_url": "https://hooks.slack.com/services/xxxxxx"
}
}
}Then run
npm init schnack