Coming Soon to the App Store

Compound your
training. Own your data.

The privacy-first fitness operating system. Structured workout tracking, AI-powered insights, and daily journaling — all on-device. No accounts. No cloud. No compromise.

Join the Waitlist See how it works
Dashboard
Fri 7 Feb
This Week's Volume
24,850 ↑ 12%
kg total across 4 sessions
Sessions
4 / 5
New PRs
3
Journal
6 days
Readiness
82%
Home
Train
Journal
Insights
You
100%
On-device privacy
0
Accounts required
0
Data sent to cloud
∞
Your data ownership
The Problem

Your fitness data is scattered across 5 apps, 3 spreadsheets, and a notes app you forgot about.

Workout loggers don't think. AI apps don't let you own your data. And nobody connects your training to your daily reflection.

🔓

Your data isn't yours

Most fitness apps require accounts and sync everything to their cloud. Your training history lives on someone else's servers.

🤖

AI that dictates, not advises

AI fitness apps generate your workouts in a black box. You don't understand why, and you can't override. That's not intelligence — it's dependency.

📊

Logging without context

You can track sets and reps anywhere. But without journaling, programme structure, and connected insights, numbers are just numbers.

The Solution

Four pillars. One system.

COMPOUND connects what other apps keep separate — your training, your planning, your reflection, and your intelligence layer.

01

Projects

Organise training into blocks, mesocycles, and phases. Each project contains workouts, documents, and goals — like a training folder that actually works.

Training Blocks
02

Workouts

Log sets, reps, and weight with minimal taps. Rest timers, plate calculators, and previous session data at your fingertips. Fast enough for between sets.

Structured Tracking
03

Journal

Daily reflection that connects to your training. Energy levels, sleep quality, nutrition notes, and freeform thoughts — all timestamped alongside your sessions.

Daily Reflection
04

Insights

On-device AI analyses your patterns. Volume trends, recovery signals, journal sentiment, and programme adherence — surfaced as suggestions, not commands.

AI-Powered Intelligence
Privacy Promise

Your data never leaves your device. Ever.

COMPOUND is built on a radical premise: your fitness data belongs to you. Not us. Not a cloud. Not a server we might sell someday. Everything runs on-device.

✓
No account required
✓
No cloud sync
✓
No analytics tracking
✓
No ads, ever
✓
On-device AI only
✓
Export your data anytime
Features

Everything you need. Nothing you don't.

⚡

Lightning-fast logging

Record a set in under 3 seconds. Previous values auto-fill. Designed for between-set speed.

🧠

On-device AI

Pattern recognition, volume recommendations, and recovery signals — all processed locally on your iPhone.

📓

Integrated journal

Daily entries linked to your training. Track energy, sleep, nutrition, and reflections alongside sessions.

📈

Progress analytics

Volume charts, 1RM progression, muscle group balance, and custom date ranges. Your data, visualised.

⌚

Apple Watch

Standalone watch app for logging without your phone. Heart rate integration via HealthKit.

🏋️

Exercise library

500+ exercises with muscle group mapping. Add custom exercises in seconds.

📦

Export everything

CSV, JSON, or PDF. Your data is always portable. No lock-in, no ransom.

🔄

Programme templates

Build and save reusable programme templates. PPL, 5/3/1, GZCL, or your own system.

🎯

PR tracking

Automatic personal record detection across every rep range. Celebrate every milestone.

Pricing

Simple. Fair. No tricks.

Start free. Upgrade when you're ready. No trials that auto-charge.

Free
£0
Forever
  • 3 active projects
  • 25 workouts per project
  • 10 documents
  • Full daily journal
  • Basic analytics
  • Exercise library
Join Waitlist
Pro Annual
£39.99 /year
£3.33/month effective
  • Unlimited everything
  • On-device AI insights
  • Advanced analytics
  • Programme templates
  • Apple Watch app
  • Priority support
Join Waitlist
Lifetime
£89.99
One-time purchase
  • Everything in Pro
  • All future updates
  • No recurring payments
  • Early access to new features
  • Founding member badge
  • Your data, forever yours
Join Waitlist
FAQ

Questions answered.

If there's no cloud, how do I back up my data?
COMPOUND stores data on-device and integrates with Apple's iCloud Keychain for encrypted backup. You can also export everything to CSV, JSON, or PDF at any time. Your backup, your choice.
How does the AI work without internet?
COMPOUND uses Apple's Core ML framework for on-device machine learning. Pattern recognition, volume analysis, and recovery signals are all processed locally on your iPhone's neural engine. No data leaves your device.
Can I import data from other apps?
Yes. COMPOUND supports CSV import from Strong, Hevy, Fitbod, and most other major workout trackers. We also support Apple Health data import for historical workout records.
What makes this different from Strong or Hevy?
Strong and Hevy are excellent loggers. COMPOUND is a fitness operating system — it connects workout tracking with daily journaling, programme management, and AI-powered insights. And unlike both, COMPOUND never requires an account or sends your data to a server.
Is there an Android version?
Not yet. COMPOUND is built native iOS-first to deliver the best possible experience. We're focused on getting iOS right before considering other platforms.
What if you shut down?
Your data lives on your device, not ours. Even if COMPOUND disappeared tomorrow, you'd still have every workout, every journal entry, every document. That's the point of privacy-first.
Coming Soon

Small inputs.
Exponential results.

Be the first to know when COMPOUND launches on the App Store. Join the waitlist — no spam, just a launch notification.