GymSync
Premium offline-first fitness tracker with zero dependencies and deterministic workout logic.
Solo Developer
Client-Side Engineering & Offline Systems
2026
Project Overview
GymSync is an 8-phase engineering project built from scratch without frontend frameworks or backend infrastructure. It provides gym-goers with an ultra-responsive, zero-latency workout companion that persists all workout logs, exercise weights, historical sets, and streak metrics locally on the device.
Structured around a centralized state resolver (getTodaysWorkout) that dynamically computes weekly training splits (Push/Pull/Legs) based on calendar days. UI views are rendered through declarative DOM mutations, while persistence is abstracted via a LocalStorage schema layer with automated weekly reset heuristics.
Deliberately built without external frameworks or build tooling to maximize mobile performance, eliminate network failure points in gym environments with poor reception, and maintain sub-16ms frame render times.
Key Capabilities & Features
Deterministic Workout Engine
Automated weekday-to-split resolver mapping target exercises, rep ranges, and sets from a unified single source of truth.
Offline-First Persistence Layer
Full local workout logging, streak advancement logic, expandable past-session histories, and weekly completion trackers.
Mobile Viewport Micro-Interactions
Custom checkbox pops, stat pulse indicators, overscroll containment, and iOS Safari input-zoom prevention techniques.