This app is still in the work, but it has a complete Auth system that is ready to be used against client apps. Once you register from the client app you will receive an access_token. There is also a verify_access_token in the Session controller method so you can use it to verify the access_tokens. You may watch the first part of my tutorial where I explain how the Rails backend works in this link. https://www.youtube.com/watch?v=ZpiF5IhavaY