Screenbeacon - Screenbeacon is a modern take on website uptime monitoring and analysis.
browserling - Live interactive cross-browser testing from your browser.
Ghost Inspector - Easily create automated browser tests for your websites and web apps. Ensure everything works and looks the way it should. No coding required. 14 day free trial!
PreFlight - Preflight is an Automated Web Testing tool. Allows everyone to automate Web UI tests.
Max Inspect - Inspect Mac apps
GoodUI Evidence - People's A/B test results that show which UI ideas work best