Solo dev, 4 months in - shipped an AI personal trainer app and just hit my first real users

Been building for a few months now and finally shipped a version so figured I'd share the journey. I'm a solutions architect by day, I got tired of fitness apps that felt like they were built by people who don't train, so I started building my own, after taking a steer from a personal trainer as to what his clients would need.

VaultTrainingClub.ai all in one solution that builds and tailors your workout plans, writes your meal plans with actual recipes, and tracks your nutrition, with an iOS and web front end

What's gone well:

Personalised AI meal and workout planning is the feature people seem to actually care about. I thought initially it would be the just the meals side of things, but the personalised custom workouts are quite unique I think....

HealthKit integration pulls in real activity data, which makes the AI workout and meal plans way more accurate

Going full-stack solo (backend, frontend, iOS, infra), must admit it was alot to get my head around but means I can ship fast without waiting on anyone, move fast and break things.

What's been hard:

Getting recipe generation to hit macro targets with the personalised nature took way more iteration than expected

Dual Auth with Azure AD B2C & Apple is powerful but the learning curve was alot more than I thought

Tech if anyone's interested: .NET 9 backend, React 19 + TypeScript web app, Swift iOS app, all on Azure.

Would love to connect with other solo founders in the fitness/health space. And if anyone wants to try it and tear it apart, I'm all ears, There's a free trial before anything paid, so have a crack see what you think.

Website: Website

iOS link: AppStore

What's your experience been with AI & personal training as a differentiator, Genuine interested or just a buzzword to most users?