To those who are not that familiar with oAuth, it's an authentication standard that defines the process of logging into a 3rd party client or app (like a Mastodon app).
So basically, most platforms like Facebook and Twitter require developers to sign up, wait for approval and rate limit their access
The magic of Mastodon is they use blind registration so you don't need approval and are subject to the same limits as all other clients, so you can allow users to login instantly. ✨