StatusGator - Monitor all your hosted applications, vendors, and websites, and keep your team informed of outages. StatusGator is the world's premier status aggregator, status page, and website monitoring tool.
Indatus - Indatus – A Creative Editor Making Your Photos Gorgeous an all-in-one photo-editing application developed by Thang Dinh.
Amazon CloudWatch - Amazon CloudWatch is a monitoring service for AWS cloud resources and the applications you run on AWS.
ClearStatus - Create your professional status page in minutes, free.
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
DigitalOcean Monitoring - Collect metrics, monitor Droplet performance, and receive alerts when problems arise in your infrastructure—no configuration required.