Implementing Touch ID and Face ID using Apple's Local Authentication framework helps prevent unauthorized access to user's data. We will use the simulator to exercise different authentication scenarios. While the passcode on an iOS device helps prevent unauthorized access, Touch ID and Face ID let the user have a more secure complex pass code, while still making the device convenient to use.
In a previous screencast we set up a simple Rails web service for todos and deployed it to production. But right now there's no authorization on it, which means anyone can come along and modify our data. In this screencast, we’ll use the Doorkeeper gem makes it easy to add authentication to Rails APIs using the OAuth 2 standard.