Skip to content
buildbyalex

Native iOS app · Fitness

Body Forge — AI Fitness Coach

A native iOS app for the gym: AI workout analysis, live set tracking, and programmes that respond to your real numbers.

Атлет со штангой в стойке для приседаний на закате — кейс Body Forge

Problem

Lifters who track workouts in a notes app lose the only data that matters — set-by-set context. Notes don't remember last week's weight. Generic 'gym tracker' apps drown the screen in graphs and never tell you what to do next. The brief was a coach in your pocket: clean tracking during the set, real analysis after, and a programme that actually adapts as you progress.

Solution

I built a native SwiftUI app for iOS. During a workout it shows the bare minimum: last week's sets, a rest timer, weight, reps — one tap to log a set. After the session, an AI coach on GPT-4o reads the whole workout — volume, intensity, progression vs the last three weeks — and writes a short, personal post-workout analysis with concrete pickups for next time ('stalled on incline press 3 weeks running — deload to 80% next week'). Programmes are first-class: an Upper/Lower split, full-body for beginners, custom blocks. The library has 200+ exercises with video form demos. Localised RU + EN.

Results

  • Live in the App Store — Body Forge: AI Fitness Coach
  • AI coach delivers a personal post-workout analysis in ~10 seconds
  • Workout screen optimised for one-handed use between sets
  • Programme library + activity rings + Apple Health heart-rate integration
The post-workout analysis is the thing. It's like having a coach who actually looks at the numbers and doesn't pretend everything is fine when you stalled.
Alex S. · Body Forge

Live in the App Store

A coach that lives on the home screen

Four screens cycle through what a typical session looks like — today's plan, mid-set tracking, the AI analysis, the programme library.

One tap from 'I'm at the gym' to 'first set in'

The home screen always opens to today's session — split type, set count, estimated time. No setup, no menus. You tap Start Workout and the rest timer is ready before the bar is.

15:07
Body ForgeS
0 days in a row
STREAK
0/7
THIS WEEK
MO
TU
WE
TH
FR
SA
SU
TODAY'S PLAN
Upper
6 exercises18 sets~72 min
AI Coach
LAST WORKOUT ANALYSIS
ANALYSIS

Your programme leans on moderate-volume strength work. You're moving solid weights — 23–28.5 kg on tricep extensions, steady progression on barbell rows. Bench has been flat 3 weeks; next session try a small deload to break the plateau.

Workout
Programs
Library
Stats

Need something similar?

30 minutes on a discovery call, and 24 hours later you have a fixed estimate.

Body Forge — AI Fitness Coach — A native iOS app for the gym: AI workout analysis, live set tracking, and programmes that respond to your real numbers. — buildbyalex