Amazon CloudWatch is a monitoring service for AWS cloud resources and the applications you run on AWS.
Monitoring, logging, and diagnostics for applications running on Google Cloud Platform and Amazon Web Services.
Cloudability lets you monitor, manage and communicate your cloud costs with one easy tool.
CloudCheckr provides security, cost and usage reporting and analytics to help users manage their AWS deployment.
Status page monitoring
Statusbot is an API for monitoring the status pages of web-based applications.