Build series · Introduction
What we’re building.
I’m building a web and mobile app for Benji, a personal trainer, and documenting the decisions, work and problems along the way.
By Ahmed Gadir3 min read
Getting an AI tool to produce a demo is quick. Turning it into an app people can rely on means getting a lot of decisions right, from the features and the design down to bookings that can’t clash and payments that fail safely. This series follows them on a real project.
I’m writing up each decision as I make it, and why. If you’re planning an app of your own, this is the job you’d be paying for, from start to finish.
Meet Benji
Personal trainer & strength and conditioning coach
Benji is the first trainer I’m building this for. I’ll show him the designs and the working versions as they take shape, and what he says will shape what gets built next. RepGarden is for other trainers too, so where his way of working is particular to him, the app has to leave room for someone who works differently.
The app
RepGarden is for personal trainers and their clients. A trainer uses a website to invite clients, set their workouts, follow their progress and take bookings. A client uses a mobile app to see the day’s workout with each exercise demonstrated, log what they lift, and book and pay for sessions. A small vegetable mascot grows stronger as they train.
Benji on Instagram
He helps combat sport athletes get stronger, faster and harder to break.
Visit @benjamin_yr ↗Screenshot from September 2026.