RegexBuddy - RegexBuddy is your perfect companion for working with regular expressions.
Proxyman.io - Proxyman is a high-performance macOS app, which enables developers to view HTTP/HTTPS requests from apps and domains.
Regex Forge - An Ultimate Regex Editor for macOS
Endpoints - View and respond to requests on an HTTP endpoint
Patterns - Patterns is a simple yet powerful tool for working with regular expressions.
httpbin(1) - HTTP request and response service