Postman, Webhook.site, and ngrok are great tools that can really enhance your API development and testing workflow. PostMan is a cross-platform API Testing Tool with lots of awesome features, Webhook.site allows you to easily inspect, test, and automate any incoming HTTP request or e-mails, and ngrok enables you to expose a web server running on your local machine to the internet.
These are must-have tools for any API developer (either creating or consuming). In short, these tools solve problems and best of all, they all have free versions which allow you to be very productive. My goal is that after this conference, you will start using at least one, if not all three, tools when you get home. I'm not saying using these tools will be life-changing, but I am also not not saying that either. - Daniel Garcia