API tools play a crucial role in making app development more simple, saving time and resources. There are numerous API tools available that assist developers with coding, testing, debugging, documentation, and more. RapidAPI Testing offers free API testing and monitoring, while Apache JMeter and SoapUI provide efficient testing solutions for performance and compliance. Other notable tools include K6 for load testing, Apigee for designing, scaling, and analyzing APIs, and Postman for designing, debugging, mocking, testing, monitoring, documenting, and more. Additionally, there are API tools like Runscope for validating complex API workflows, Bugsnag for detecting automated crashes, Swagger for visualizing and interacting with API resources, 3scale for building API infrastructure, RAML for managing the entire API lifecycle, Apiary for writing and sharing APIs, Hoppscotch for building requests, Insomnia for designing, debugging, and testing solutions, SwaggerHub for documentation purposes, ReDoc for open-source API documentation, Docco for in-source documentation, DapperDox for OAS 2.0 and OAS 3.0 support, and API2Cart for eCommerce integration. RapidAPI Enterprise Hub and Client provide solutions for finding, managing, connecting to APIs and external subscriptions, accelerating API delivery, and enhancing developer experience.