Zendesk - Zendesk is a beautiful, lightweight help-desk solution.

PagerDuty - Cloud based monitoring service

Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community

OpsGenie - Alerting and On-Call Management for Dev&Ops Teams

Abhisi - Abhisi provides a helpdesk solution that seamlessly integrates with all communication channels used by the customers.

xMatters - xMatters transforms event data into intelligent communication IT teams, avoiding outages and disruptions