Trello for Slack - Organize anything with anyone, inside Slack
PagerDuty - Cloud based monitoring service
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
OpsGenie - Alerting and On-Call Management for Dev&Ops Teams
Halp - Slack-first ticketing for internal helpdesk
xMatters - xMatters transforms event data into intelligent communication IT teams, avoiding outages and disruptions