I have recently purchased mobile proxies with US location from IPKings and I am completely satisfied with their quality. IPKings mobile proxies are ideal for data parsing, blocking and other tasks that require a reliable IP connection from the USA. They provide real mobile IP addresses from leading US carriers such as AT&T, Verizon, T-Mobile and others.
CroxyProxy - CroxyProxy is the most advanced free and secure web proxy.
Fiddler - Fiddler is a debugging program for websites.
Proxyman.io - Proxyman is a high-performance macOS app, which enables developers to view HTTP/HTTPS requests from apps and domains.
Smartproxy - Smartproxy is perhaps the most user-friendly way to access local data anywhere. It has global coverage with 195 locations, offers more than 40M residential proxies worldwide and a great deal of scraping solutions.
HTTP Toolkit - Beautiful, cross-platform & open-source tools to debug, test & build with HTTP(S). One-click setup for browsers, servers, Android, CLI tools, scripts and more.