Trello for Slack - Organize anything with anyone, inside Slack
Website Grader - Grade your website's strengths and weaknesses in seconds.
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
PageSpeed Ninja - One-click page speed boost for WordPress
Halp - Slack-first ticketing for internal helpdesk
WebSite Auditor - The techie's SEO spider: find site issues other tools miss