Free openGym Fitness Tracker Replaces Paid Apps with 1,324 Exercises and Offline Mode

For strength training and fitness enthusiasts, openGym offers an open-source, free workout tracker. The app operates without paid subscriptions, ads, or cloud account requirements, featuring a catalog of 1,324 exercises, automated progression algorithms, and local-only workout history storage.

The service was created as an independent alternative to commercial mobile workout logs.

Exercise Catalog, Smart Progression, and Muscle Heatmap

The built-in library includes animated instructions with filtering by muscle groups and equipment, while also allowing users to create custom exercises.

During sets, the app automatically pulls working weights from the previous session, manages a rest timer, logs new personal records, and calculates a theoretical one-rep max (1RM). It also supports supersets, warmup sets, timed exercises, and Rate of Perceived Exertion/Reps in Reserve (RPE/RIR) tracking.

The app comes preloaded with popular progressive overload schemes: Linear Progression, Greyskull LP, and Double Progression. It displays target weights for upcoming workouts in advance, while an interactive muscle heatmap visualizes training volume, estimated fatigue, and recovery time for specific muscle groups.

Weight Tracking and History Migration from Strong and Hevy

Body weight progress is tracked on a dedicated chart with target goals. Full workout history is visualized through a GitHub-style yearly activity graph showing training streaks and missed days.

Users can seamlessly migrate their old workout logs with data import support from FitNotes, Strong, and Hevy, as well as body weight exports from Apple Health and full JSON backup downloads.

🚨 LE TUMBARON EL GITHUB A ESTE DEV.

Y todo por publicar GRATIS una app de entrenamiento que no te pide cuenta, suscripción ni guardar tus datos en la nube.

Se llama openGym.

Es un tracker de entrenamiento con el que puedes:

→ Planificar tu semana
→ Seguir entrenamientos… pic.twitter.com/O0FqHcPCAA

— Fran Pradas | Ingeniero de IA (@franpradasAI) August 25, 2026

Complete Offline Functionality, PWA, and MCP Support

According to the official GitLab repository, the project is distributed under the open-source AGPL-3.0 license with zero telemetry or hidden fees:

• For Android: an ultra-lightweight 4.4MB APK is available that requires no internet connection;
• For iOS and desktop: the system can be self-hosted and used as a Progressive Web App (PWA) with Face ID or Touch ID (Passkey) biometric authentication and cross-device syncing.

According to openGym documentation, the developer integrated a local MCP (Model Context Protocol) server, allowing external AI assistants like Claude to analyze workout history in read-only mode.

Users can test the interface features without downloading files via the web demo on the project’s official website.