I have long used `postman` and, on the Mac, `Paw.app` to test REST calls. But today a co-worker turned me on to the VSCode extension "REST Client". I use VSCode anyway, and this client is awesome. Plus, I can get rid of some extraneous tools then. But holy mackerel it is awesome.
geekstream.org is the personal mastodon instance. It is not open for mastodon account registration.