I've spent years building an ambitious offline fitness app. Now I'm seriously considering making it free and community-developed. I'd love some honest opinions.

I'm a personal trainer and gym manager who's become increasingly frustrated with the state of fitness and coaching software. Expensive subscriptions, half-baked applications, unnecessary cloud dependencies and questionable data privacy practices.

So I started building True Grit, a premium, entirely offline workout tracking and coaching application written in Flutter.

It's a massive undertaking, nowhere near finished, and probably more feature-packed than most people will ever need. But what I've built so far works incredibly well, and I've put an enormous amount of time and effort into getting it where it is today.

Some of its current functionality and ongoing development:

Workout tracking: The centrepiece of the application. Fast, intuitive logging with an overview mode displaying individual exercises in dedicated containers, alongside a guided, full-screen experience that takes you through your workout in sequence.
Media library and editing: A functional photo library and non-destructive editor using custom multi-stage shaders, with an interface inspired by premium photography applications. Performance optimisation is still ongoing, with video support planned.
Social exports: The goal is to produce beautiful, customisable workout summaries, progress photographs and comparison exports, complete with personal branding and optional overlays of linked training or client metrics. Parts of this are still in development.
Advanced analytics: Ambitious progression and comparison functionality, eventually allowing different training and performance metrics to be overlaid on the same graphs to explore relationships between them.
Bespoke training decay modelling: Inspired by Banister's impulse-response model, incorporating three separate streams of training data to help estimate training adaptations and recovery.
Custom interface: A bespoke calendar, dialogs, navigation and components built around the Liquid Glass widgets package for Flutter.
Cross-platform architecture: Built in Flutter, with plans for a dedicated desktop coaching interface offering a more spacious experience for client management and programme creation.
Much more to this too but i'd be here all day...

And perhaps the most important part? Everything is entirely local.

No mandatory accounts. No subscriptions. No cloud dependency. No vendor lock-in.

Your database, photographs and training history belong to you. Back them up wherever you want, migrate between devices and continue training regardless of your internet connection.

The longer-term vision is to allow coaches to create programmes and distribute them to clients through portable packages, with clients returning their completed training data just as easily.


I want the software to support the relationship between coaches and athletes, not replace it or make either party dependent on an expensive third-party platform.

But here's my dilemma.

I originally intended to sell True Grit. However, seeing the extraordinary pace of AI-assisted development, reverse engineering and feature-by-feature software reimplementation has made me reconsider the future of proprietary software.

I'm now seriously considering releasing True Grit completely free, publishing its source code and inviting community contributions.

Not because I think the work I've put into it is worthless, but because I genuinely believe the project could become something much more meaningful if other people were able to contribute to its development.

I'd love to see developers, coaches, athletes and researchers collectively improve it. Perhaps even establish open standards for exchanging training data that other applications could eventually adopt.

My biggest reservation is commercial exploitation.

I have absolutely no interest in companies taking the code, repackaging it and charging people for software intended