I used AI to code a personal trainer app in one weekend. I see why big apps fear the competition.

Mădălin Mihai

As a former group fitness coach, I was trained to track my goals in numbers: calories in, hours trained, kilograms lifted. Numbers don't lie. However, tracking them was messy. I bounced between MyFitnessPal for meals, Apple Watch for workout duration, and the Notes app for lifting logs. When I needed help with the form, I'd scroll through videos online between sets. It took the joy out of the gym. At a vibe-coding workshop in Singapore in February, I tested a simple idea: What if all of this