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.
SaaS 1000 - Free exportable list of the fastest growing SaaS companies
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Inside SaaS Sales - 1000+ sales emails and voicemails from top SaaS companies
Better Uptime - We call you when your website goes down
pickSaaS - Hundreds of SaaS products, analyzed.