Lowdown - Lowdown unleashes the valuable content locked within Slack and emails it to your members so they don't miss key information.
Hyperping - Cheap uptime and performance monitoring with detailed reporting and flexible alerting
Scrumbot - A summary of all team data in Slack before your daily scrum
UXPin + Slack - Keep tabs on design projects in Slack
Marketplace Hacks - A slack community of marketplace founders & operators
WebGazer - Monitor your website's availability with WebGazer, review its performance and get instant notifications when your website goes down. No installation required and free plan available.