On the 9Lessons.info site they've posted a tutorial walking you through the creation of an application using Iconic 3, Angular 4 and a PHP restful API and how to handle user authentication and signup. It's a continuation from this previous post that kicked off the series.

Today’s post explains how to implement login authentication system for your AngularJS applications. It will show you how to log in with a user and store the user session, so it deals with token based authentication. Since we are using token based authentication, it protects if any unauthorized request is made and notices for a new login if required. This makes your application’s authentication to be more secured compared with any other authentication system. Every user details will be stored in an external database and a PHP based API is used in the backend for handling this authentication. Hope you’ll find it more easily using this as your authentication system in your AngularJS projects.

They assume you've worked through the previous post and already have the basic structure of the application set up. They share a screencast showing the process but also include the key details - database tables, code and markup - in the post for those that prefer to follow along that way.