I made a simple workout planner. You can try it here: Workout Planner

After documenting the design and the intended workflow manually, I vibe-coded the UI with ChatGPT Codex. It’s another rep of experience creating a nice application quickly - it probably took me 3h in total.

I’m getting a better feel for what components you can hand off to a coding agent, what components it’s easier build yourself, and what the workflow feels like when it all comes together smoothly.