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.
Eyequant - We’ve built an artificial intelligence that instantly predicts how users will see your website so that you can create landing pages that sell
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Attention Insight - Maximize advertising campaign results and design performance with pre-launch analytics.
Better Uptime - We call you when your website goes down
VisualEyes.design - Instant visual analysis of websites to perform competitor analysis or conversion rate optimization.