WebGazer is an uptime monitoring platform that checks if your website is up as it should be and notifies you if anything goes wrong
UptimeRobot - Free Website Uptime Monitoring
Lolli - Earn bitcoin when you shop online
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Paribus - Find out for free if online stores owe you a refund!
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.
Slice Watch - Get an email when an item you've added drops in price 💸