Sentry.io - From error tracking to performance monitoring, developers can see what actually matters, solve quicker, and learn continuously about their applications - from the frontend to the backend.
Whoisology - Connected database of whois records and whois history
Rollbar - Rollbar collects errors that happen in your application, notifies you, and analyzes them so you can debug and fix them. Ruby, Python, PHP, Node.js, JavaScript, and Flash libraries available.
Bulk Whois API - Bulk Whois API is a provider of parsed WHOIS data in JSON with simple API, competitive pricing, top notch support, and more.
RootCause - Record, Replay and Reproduce JavaScript Errors
WhoisAPI - WhoisAPI is the premier provider of freshly parsed whois data for domain names and IP addresses...