For someone who had never touched Apple's Swift development before, I was amazed to find that—with the help of AI—I could actually build a complete app. Here's my story. One evening, while walking with my mom, we talked about how many Chinese apps are overloaded with ads. She casually complained that the calendar app she was using was full of them. I was surprised—why not just use Apple's built-in Calendar? She explained that it didn't have the features she needed, like public holidays and the traditional Chinese almanac. At that moment, a lightbulb went off: I already had a developer account, so why not just build one myself? So I opened up AI and asked: "Can you write me a Swift calendar app with a beautiful UI that supports dark mode?" Almost instantly, AI generated the code. When I ran it, the interface looked great. Next, I needed to display holidays. Since I had no budget, AI suggested using the free holiday API provided by timor.tech. It not only integrated the API but also added local caching so the app would still work offline. I then asked for a "year view" with color-coded holidays, and AI delivered. For the almanac feature, AI generated a JSON dataset and wrote an algorithm to process it. I noticed the results didn't always match other calendar apps. AI explained that different "calculation standards" exist and even added a toggle so users could switch between them. Once that was done, I asked it to adapt the app for visionOS and macOS—AI handled that smoothly too. Since all of the code was generated in one go, what I had was just a single, very long file without any modular structure. When I first submitted it to the App Store, Apple rejected it under Guideline 4.2: Design—Minimum Functionality. I went back, asked AI to add push notifications and a welcome screen, and on the next submission, it finally passed review.