Web Load Speed Test - Test your website load speed from 6 locations at once
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.
Loadium - Performance Testing & Load Testing Tool
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Blazemeter - BlazeMeter is a self- service performance load testing cloud tool
Better Uptime - We call you when your website goes down