httpbin(1) - HTTP request and response service
ProntoForms - ProntoForms is a mobile business solutions application, converting paper forms onto any tablet or mobile device.
HTTPDump - A simple, beautiful Webhook debugging tool.
Safety Culture - SafetyCulture is the operational heartbeat of working teams around the world. Its mobile-first operations platform leverages the power of human observation to identify issues and opportunities for businesses to improve everyday.
Proxyman.io - Proxyman is a high-performance macOS app, which enables developers to view HTTP/HTTPS requests from apps and domains.
GoFormz - GoFormz provides a complete mobile forms and reporting solution.