I would like to know about the ideal plan to enable authentication for mobile apps using Ionic Framework. I can think of the following two ways, but I am not sure how to proceed further.

1. Token based auth on Backend services (Express + MongoDB)
2. First Page sign up and forget as users can't access the url properties

Please suggest any other options you might have in mind and a broad explanation is more than welcome. I am looking forward to learning about the easiest way to do this.

Thanks.