Redsmin - All-in-One GUI for Redis. Thightly crafted developer oriented, online real-time monitoring and administration service for Redis.
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.
usql - Universal command-line interface for SQL databases
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Errbit - The open source error catcher that's Airbrake API compliant
Better Uptime - We call you when your website goes down