Pingdom - With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.
Slack - A messaging app for teams who see through the Earth!
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Microsoft Teams - Microsoft Teams provides the enterprise-level security, compliance and management features you expect from Office 365, including broad support for compliance standards, and eDiscovery and legal hold for channels, chats, and files.
Better Uptime - We call you when your website goes down
Project Pulse - Project status pages communicate progress for you