The app itself is trivial. What mattered to me was the time it took to build.
I don’t know Swift and had never written a macOS app before. Based on past experience, I’d estimate that learning enough Swift, figuring out the macOS APIs, implementing the logic, and testing would normally take me 3–4 days.
Using Gemini Pro (via Antigravity), almost all of the code was generated by AI, and the whole thing took about an hour.
This is obviously a tiny project, but yet another data point on how software engineering is changing.