Let's Build That App is the iOS-development teaching brand of Brian Voong, a former Goldman Sachs and Facebook engineer who now publishes full app-build courses for SwiftUI and UIKit. The channel is one of the most prolific independent iOS-tutorial sources on YouTube, with paid extended versions on his site that walk end-to-end through real-app projects.
His CourseFlix material reflects that approach: SwiftUI Mastery Travel Discovery, Instagram Firebase (a from-scratch Instagram clone with a Firebase backend), and Ultimate SwiftUI Mock Interview AppStore all follow the same structure — the instructor builds a complete shippable iOS app on camera, dropping into Xcode shortcuts, simulator behaviour, and Apple framework idioms as the project demands them.