HttpMaster - HttpMaster is a professional software tool for testing and debugging HTTP applications, primarily aimed at REST API applications and web services.
Skuuudle - Discover, match and monitor your eCommerce competitors.
Hoppscotch - Open source API development ecosystem
Prisync - Prisync is a competitor price tracking and monitoring software for all sizes of e-commerce companies worldwide.
MockServer - Easy mocking of any system you integrate with via HTTP or HTTPS.
Price2Spy - Price2Spy is a price monitoring, pricing analytics, and repricing tool, meant to help eCommerce professionals keep an eye on their competitors or retailers.