ProofPack was my first real mobile app. Not a tutorial project. Not a prototype. An actual app that I built, submitted, and published on the Play Store.
It took longer than I expected and broke more than I wanted. But it taught me things that no course or tutorial could have — because it was real, and real things break in ways that tutorials do not.
The biggest thing I got wrong was scope. My original idea for ProofPack was enormous. I wanted it to do ten things. I built the version that did one thing well, and even that took three times longer than I expected. I dread to think how long the ten-thing version would have taken.
The second thing I got wrong was how I used AI. For the first few weeks, I treated Codex like a magic wand. I would paste enormous blocks of code and ask it to "fix everything." The results were unpredictable. Sometimes it helped. Often it made things worse. I did not understand why until I started asking for one fix at a time.
What I got right was GitHub. From day one, I committed after every working change. This saved me at least four times. Once when Codex rewrote half my navigation by accident. Once when I updated a dependency and everything broke. Once when I deleted a file I thought I did not need. GitHub was the difference between losing a week of work and losing an afternoon.
The thing I am most glad I did was document everything as I went. Every prompt that worked. Every error I hit. Every fix that solved it. That documentation became the foundation for what I now share on NonDev Apps.
If I started today, I would do three things differently. I would start with a much smaller idea. I would commit to GitHub every thirty minutes instead of once a day. And I would write my prompts as if I were explaining the problem to a careful friend — not shouting at a magic box.