Postman is a management application, developed by Postman Inc., that provides users the means to test APIs by building HTTP requests, while also being able to sync the API to the cloud in order to share data with the team.
The app comes with a nicely crafted interface and has a rich main menu, with lots of tabs and buttons, and can be a bit overwhelming for a novice user. However, experienced users will find the GUI quite intuitive and well-delimited. The only noticeable con is the poor grouping of tests, as it's a bit difficult to manage them.
To sum it up, Postman is a powerful tool for managing APIs, and it helps professionals to improve the efficiency of their work. Still, the documentation could've been organized better, while the authentication can be difficult at times.