Are you looking for a useful API (application program interface) tool? We have shortlisted some of the tools that can help you in building software applications.
Apigility
One of the easiest tools to create high-quality APIs. It enables you to get started creating their first API in just a few seconds. It supports all PHP frameworks and libraries as well as OS including Windows, Linux, and OS X.
Falcon
This one is one of the fast and flexible API tools that works on Python framework for building cloud APIs and web app back-ends. It supports all the major operating system such as Windows, Linux, and OS X
LoopBack
This API tool claims to be as a "powerful Node.js framework for creating APIs and easily connecting to backend data sources." The tool supports all the operating systems inclusing Windows, Linux, OS X, Android, and iOS.