To publish an iOS app, developers must first obtain an Apple Developer license, which is free but an iOS developer license costs $99. The app must then be thoroughly tested on different iOS devices before submission. It should not crash, use private APIs, or replicate native app functionality. Proper app assets, metadata, and compliance with App Store guidelines is also required. Finally, the app is submitted through iTunes Connect, priced, and the information is reviewed before the binary is uploaded from Xcode for final review.