WP SlackSync - Synchronize Slack channels + chats with your Wordpress site
PloyRef - Automated employee reference checking
Slackin - Create your own public Slack chat community
Tomigo - Tomigo is a social recruiting platform that leverages your company's social connections to hire top talent.
Hamster Pad - A social network built on top of Slack
WorkGrades - WorkGrades is the best software for gathering and managing your work references.