I use Postman some times and I really hate the need to open Chrome just for that. Even worse, I can't use Alfred to open directly the Postman app and of course I will not use that Chrome App Launcher invention.
I created a Workflow to open Postman from Alfred directly. Probably you will have to tweak the url of the Postman web app to match with yours. You can just copy the URL from the address bar.
This should be easy.