Overview
FitTune is a mobile-first fitness tracker for strength training and endurance activities. I am building it around the work of actually completing a session: choosing a routine, logging sets, checking exercise history, and reviewing progress afterwards. Runs, rides, and other activities sit alongside strength workouts rather than requiring a separate tracking tool.
Training That Stays Editable
Workouts record exercises, sets, repetitions, weights, and the tracking fields needed for timed or distance-based activities. Reusable routines and a library of training templates provide starting points that remain editable. Where usable exercise history exists, template weights can be filled from previous sessions instead of making the user start from scratch.
Workout places record the equipment available at home, at the gym, or at a custom location. The exercise picker uses that equipment to help users find exercises they can perform there. Changing the place does not silently remove exercises from a workout.
Offline Workout Logging
An active workout is saved locally as the user logs it. The interface updates immediately, and background synchronization sends versioned snapshots to the API when a connection is available. Completed offline workouts wait in an outbox, so a poor connection does not have to interrupt the session.
The React application is installable as a PWA. Its service worker caches the application shell, while a persisted TanStack Query cache keeps previously downloaded history and exercise data readable offline. An update prompt lets users choose when to load a new version rather than forcing a reload in the middle of a workout.
History and Progress
FitTune brings together workout history, exercise records, activity logs, and progress charts. The interface adapts to the device: large controls and a bottom navigation on phones, with denser history and analytics layouts on desktop. Charts also provide table views.
Progress photos are optional and separate from saving a workout. Uploads are handled by the API and stored privately, with image metadata removed during processing.
Application and API
The frontend uses TypeScript, React, TanStack Router, TanStack Query, and Zustand. Zod validates API responses at the client boundary. The backend is a separate Rust service built with Axum, Tokio, SQLx, and PostgreSQL.
The API owns accounts, sessions, the exercise catalog, routines, workout documents, and analytics. Workout writes use client-generated identifiers and revision checks, making retries safe without creating duplicate sessions. The client and backend communicate through an explicit HTTP contract and have separate release workflows.
Deployment
The frontend is built as static assets and served through Caddy on a shared VPS. Versioned releases switch atomically and keep recent builds available for rollback. The API runs separately, with database migrations and authenticated access to user data.
FitTune is still in development, with the focus on making training quick to record and useful to revisit.