StatusPage.io - StatusPage.io is the best way for web infrastructure, developer API, and SaaS companies to get set up with their very own status page in minutes. Integrate public metrics and allow your customers to subscribe to be updated automatically.
Apache Airflow - Airflow is a platform to programmaticaly author, schedule and monitor data pipelines.
UptimeRobot - Free Website Uptime Monitoring
ifttt - IFTTT puts the internet to work for you. Create simple connections between the products you use every day.
FreshStatus - Better status pages in 1-click, FREE FOREVER
Pushwoosh - Mobile-inspired customer engagement platform for high achievers