Welsh Personal Trainer Creates AI-Powered App to Improve Gym Training

Millions of people around the world go to the gym every day without ever receiving a single lesson on how to lift correctly. A qualified personal trainer from Caerphilly, Wales wants to change that – and he has built an AI-powered app to do it.

RepCheck, founded by Kian White, is not designed to replace personal trainers. It is built for the vast majority of gym-goers who do not have one – people who train alone, who cannot justify the cost of regular PT sessions, or who simply want personalised feedback on their technique without booking an appointment. The app analyses video footage of users performing key gym exercises and delivers instant, personalised technique feedback designed by a qualified personal trainer, directly to their phone, for just 7.99 pounds a month.

Using AI and pose detection technology, RepCheck scores users across five form categories for each of the four core lifts – squat, deadlift, bench press and overhead press – and returns coaching cues written in plain English, in the same language a real personal trainer would use on the gym floor.

The app launches on the iOS App Store this autumn with a three-day free trial and no payment required to get started.

The inspiration for RepCheck came from years of watching people train hard but make slow progress – or worse, get hurt – because they had never been properly taught how to move.

Not everyone wants a personal trainer. Not everyone can afford one. And that is completely fine, says Kian. But that should not mean they have to train without any feedback at all. The gap between people who have access to good coaching and people who do not is enormous. RepCheck exists to close that gap.

Poor technique can be difficult for inexperienced lifters to identify, particularly when training alone without professional feedback. RepCheck is designed to highlight potential technique issues that users may otherwise overlook – helping them to train with more confidence and greater awareness of how they are moving.

Bad form does not always cause problems straight away, Kian explains. It can build up over time. RepCheck is designed to give people the kind of feedback on their lifting that they would otherwise only receive from a qualified coach.

The process is simple. Users select their exercise, film a short video of their lift from the side on their smartphone, and upload it to the app. RepChecks AI engine maps joint positions frame by frame, calculates movement angles and compares them against established form parameters.

Results are delivered as plain English feedback – not technical data or jargon. Users receive an overall form score out of 100, a breakdown across five movement categories, a key coaching cue, specific feedback points and a focus area for their next session. Every analysis is saved so users can track their improvement over time.

Kian White, Founder of RepCheck, said:

“The feedback is designed to sound like a real PT because it was designed by one. I wrote every coaching cue based on what I would actually say to a client standing in front of me. That is what makes RepCheck different.”

RepCheck has been built entirely independently by Kian, who has continued running his personal training business throughout the development process. The project has been self-funded from the start – a bootstrapped startup from South Wales with global ambitions.

“I am a PT, not a tech founder. Getting this built has required an enormous amount of learning. But I genuinely believe this is something the fitness world needs – and that belief has kept me going through every setback along the way.”

The app is currently in beta testing with early users ahead of its full App Store launch this autumn. A founding member pricing tier at 4.99 pounds per month is available to the first 50 subscribers.

The global fitness app market is projected to exceed 15 billion dollars by 2026. While established apps focus heavily on nutrition, workout logging and activity tracking, RepCheck is focused specifically on movement quality and lifting technique – an area that has historically required one-to-one coaching to address properly.

“Every fitness app tells you what to do. RepCheck tells you how you are doing it. That is the gap we are here to fill – for everyone, everywhere, regardless of whether they have ever worked with a personal trainer.”

RepCheck launches on the iOS App Store this autumn. Android support is planned for a subsequent phase.