Developing an iOS app for the first time is no small feat—especially when starting from scratch with no prior experience in Swift. Yet, one developer recently achieved this milestone by relying entirely on Codex as his primary coding partner. Over four months, he built Rushi, a Buddhist toolkit featuring a sutra reader, a 108-bead mala counter, and sutra calligraphy practice tools. The app launched successfully on the App Store, supported in 17 languages, and maintained zero crashes during beta testing.
Starting from zero: learning Swift with Codex
Before beginning this project, the developer had never written a line of Swift. Codex served as both a mentor and a collaborator, enabling him to learn the language by doing—building the app feature by feature. The toolkit’s core functionality revolves around religious texts, requiring meticulous attention to localization and cultural nuances. Rushi was released as a free download for the first week, followed by a $1.99 price point, with early users granted lifetime access regardless of future pricing changes.
Codex’s strengths in iOS app development
Several aspects of the development process benefited significantly from Codex’s capabilities. One of the most notable was its ability to generate SwiftUI layouts from natural-language descriptions. Initial iterations of the app’s interface were not only functional but also visually coherent, with approximately 80% of layouts matching the first draft without major revisions.
Localization presented another area where Codex excelled. The developer needed to support 17 languages, including complex scripts like Vietnamese and Tibetan. Codex autonomously created all .strings files from English seed phrases, demonstrating cultural awareness—for example, selecting appropriate Vietnamese honorifics for Buddhist terminology and ensuring accurate Tibetan transliterations.
Mid-project schema changes required SwiftData migration code, a task that Codex handled efficiently. Additionally, when Apple’s UIFont in iOS 17 failed to render Chinese serif fonts correctly, Codex recommended a workaround using CTFontDescriptor with explicit fallback chains, resolving a critical visual issue.
The developer also used Codex to generate keyword lists for Apple Search Ads, which closely matched the high-volume terms later confirmed by the platform’s actual data.
Challenges and manual interventions
Despite Codex’s strengths, certain areas demanded hands-on adjustments. Apple-specific user experience nuances, such as precise haptic timing, large title behavior, and dynamic type quirks, required multiple rounds of testing and visual feedback. Codex’s suggestions often missed these platform-specific details entirely.
Audio concurrency posed another hurdle. Codex tended to overcomplicate solutions using modern concurrency models like actors, whereas a simpler approach with AVAudioPlayer would have sufficed. This highlighted the importance of understanding when to override AI suggestions.
App Store metadata also required careful oversight. Codex occasionally proposed incorrect privacy label classifications or age ratings, such as marking data collection as false while simultaneously suggesting the integration of an analytics SDK in another file. These discrepancies underscored the need for developers to verify AI-generated metadata against actual data flows.
Practical tips for solo developers using Codex
To maximize Codex’s effectiveness, the developer recommends several best practices. When iterating on SwiftUI views, providing Codex with the complete file—not just snippets—leads to more accurate layout adjustments. Similarly, when debugging, pasting the exact Xcode error text, including line numbers, helps Codex map stack traces effectively and produce targeted fixes.
For App Store submissions, Codex can draft privacy label statements, but developers should cross-reference these against real usage to avoid discrepancies between stated policies and actual data collection. Additionally, Codex’s dependency recommendations often favor popular libraries over minimal ones—a mismatch for solo developers aiming to keep app sizes lean. Manual evaluation is crucial in these cases.
Results and reflections
Rushi cleared Apple’s review process in just two days with no rejections. The final app supported 17 UI languages and nine full-text languages, ensuring broad accessibility. TestFlight beta testing revealed no crashes, a testament to both Codex’s code quality and the developer’s diligent oversight. The project’s source code and the open-source sutra texts are now publicly available on GitHub under CC0 1.0 licensing.
During development, the developer consumed around 50 million input tokens and 3 million output tokens through Codex. While vibe coding initially caused anxiety, the iterative, hands-on process of building Rushi ultimately brought a sense of calm and accomplishment. The experience proves that AI can be a powerful ally in solo development, provided its outputs are carefully validated and refined.
For developers curious about the intersection of AI and mobile development, Rushi’s journey offers valuable insights into leveraging Codex without relinquishing creative control.
AI summary
Tek başınıza iOS uygulaması geliştirirken Codex’in sunduğu faydalar ve karşılaşılan zorluklar. SwiftUI, SwiftData ve çok dilli yerelleştirme süreçlerinde neler öğrendiniz?
