WebGazer - Monitor your website's availability with WebGazer, review its performance and get instant notifications when your website goes down. No installation required and free plan available.
BiggerCake - The data tool that Kickstarter deserves
Hyperping - Cheap uptime and performance monitoring with detailed reporting and flexible alerting
Campaign Monitor Insights - Actionable analytics for email marketing and automation
NIXStats - SaaS monitoring tool for window/linux servers and websites. Think up-time robot but with more features.
Snov.io - More leads. More sales. More revenue.