Add 2FA to iOS Apps with Swift and Nexmo’s Verify API

The tutorial outlines how to implement two-factor authentication for a user's phone number using Nexmo's Verify API endpoints in an iOS app. The process involves setting up the Glitch server, programming the UI to request or respond to requests with the server, and implementing functions to send SMS verification requests and verify PIN codes. The implementation includes storing a response ID to cancel or complete verification requests, making network calls to start, check, and cancel verification requests, and handling successful and unsuccessful verifications. The app's UI is reviewed, including a verification view controller with text fields for inputting email address, password, and telephone number, as well as buttons for login and cancel verification.