Iron Church is live on the iOS App Store. After a year of building and twelve weeks of live testing, the AI personal trainer built around Brodin — an iron god who is openly, plainly an AI — is available to download for iPhone, and free to try in any browser.

 Download Iron Church on the App Store
Or take the 60-second Naming quiz first — Brodin will name your training style, free, no account.

What is Iron Church?

Iron Church is an AI personal training app for iPhone and web. It generates periodised, progressive strength-training programmes across 21 training disciplines — from powerlifting and novice linear progression to bodybuilding, 5/3/1, calisthenics, kettlebell Grease-the-Groove, and hybrid strength-plus-endurance training — each governed by its own programming rulebook. Sessions adapt to what you actually logged: your loads progress off your last session, a daily readiness check tunes today's intensity, and over-worked muscles drop out of your exercise pool until they recover.

The coach is Brodin — a bearded iron god with three millennia of opinions, voiced by a large language model. You can talk to him: ask him to swap a movement around a sore shoulder and the swap lands in your actual programme, not just the chat.

Is it really AI, or a chatbot in a costume?

Most "AI" fitness apps are rule-based template systems with a chat interface on top. Iron Church runs the opposite architecture: a real LLM narrates and reasons, while deterministic code computes every number. Estimated 1RMs use the published Brzycki, Epley, and Mayhew formulas selected by rep range. Every prescribed load is snapped to plates you can actually rack. Weekly hard sets per muscle are tracked against research-informed volume landmarks. The AI is never allowed to guess at the maths — validators check its work before you see a session. We call this honest AI: the app tells you plainly what the model does and what the engine does.

What is The Naming?

The Naming is a free 60-second quiz, in Brodin's voice, that names your training discipline. Five questions — what you're hungry for, how long you've trained, how many days you can give, what equipment you have, and what a session that feels right feels like — and Brodin names one of the 21 paths as yours, with the discipline's history, what the first weeks are like, and your first workout laid out. It needs no account and no card, and if you claim the path, the app remembers your answers when you sign up — on any device, via a six-character seal code.

How much does Iron Church cost?

  • Free tier — five AI-generated sessions, unlimited hand-built programmes in the Forge, PR tracking, muscle heatmap, and community access. No card required.
  • The Faithful — £7.99/month or £79.99/year for unlimited AI programming, long-range campaign planning, the exercise swap engine, and priority coaching. Cancel anytime.

For comparison, the established AI-coach apps in this category list at roughly $300–$400 per year — for rule-based, single-method systems.

What platforms does it run on?

Iron Church is on the iOS App Store now, and runs free in any modern browser as an installable web app at theironchurch.co.uk. Android is on the way. Completed sessions sync to Strava with your exercise list, PRs, and Brodin's verdict.

Who builds it?

Iron Church is built by one person — James John Bell, previously Head of AI at Dow Jones, a Fellow of the British Computer Society, and a lifter — shipping daily. The engineering story, including why the model is a commodity but the context is the product, is covered in earlier dispatches.

Stop guessing. Start training.
Download on the App Store · Let Brodin name your path