BrandHunt V2 - Search/track domain & social media handles in real time.
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.
Lean Domain Search - Find a Great Domain Name w/ twitter handle availability
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Zoho Social for Agencies - A single platform serving all your clients
Better Uptime - We call you when your website goes down