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VoxDroid/CycleOne

CycleOne

CycleOne App Icon
A privacy-first, sophisticated menstrual cycle & fertility tracker for iOS.

Platform Swift License Privacy


Overview

CycleOne is a high-performance, open-source period tracker designed for users who value privacy above all else.

In an era of cloud-connected health apps, CycleOne takes a stand: Your health data is yours alone. Built with a strict "local-only" architecture, it provides professional-grade cycle prediction, symptom tracking, and historical analysis without ever requesting network access, requiring an account, or charging a subscription fee.

Core Features

Visual Preview

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Advanced Prediction Engine

  • Period Projection: Intelligent estimations for start dates and duration based on historical averages.
  • Ovulation Tracking: Automatic calculation of ovulation and fertile windows.
  • Irregularity Alerts: Identifies significant cycle variances to help you remain aware of physiological shifts.

Holistic Logging

  • Flow Intensity: Categorical tracking from spotting to heavy flow.
  • Symptom Database: Track physical, emotional, and digestive indicators.
  • Mood & Energy: Document biometric indicators with a streamlined, premium UI.
  • Notes: Local-only annotations for detailed record-keeping.

Premium User Experience

  • Native Calendar: Leveraging UICalendarView for a high-contrast, interactive experience.
  • Dynamic Themes: 5 custom accent color themes (Rose, Lavender, Ocean, Sage, Sunset) to match your style.
  • Smooth Animations: High-fidelity transitions and staggered animations for a premium app feel.
  • Zero Emojis: A consistent, professional aesthetic using high-quality SF Symbols.

The Privacy Manifesto

CycleOne was built from the ground up to be safe:

  • No Cloud Sync: Your data never leaves your device.
  • No Accounts: No email, no password, no login required.
  • No Analytics: Zero third-party tracking or telemetry.
  • No Network Entitlements: The app doesn't even ask for internet permissions.
  • Data Sovereignty: Export your entire history to CSV anytime.

Technical Specifications

Component Technology
Language Swift 5.9+
Framework SwiftUI with MVVM Architecture
Logic Proprietary CycleEngine (Pure Swift)
Persistence Core Data (On-device SQLite)
Interface Native UIKit/SwiftUI hybrid
Testing 100% Test Coverage (XCTest)

Getting Started

Prerequisites

Development Setup

  1. Clone the repo:
    git clone https://github.com/VoxDroid/CycleOne.git
  2. Install pre-commit hooks:
    brew install pre-commit
    pre-commit install
  3. Open CycleOne.xcodeproj and build for the simulator.

Workflow Commands

We use a Makefile for CI/CD consistency:

  • make check: Full verification suite (Lint, Format, Test).
  • make unit-test: Execute logic tests.
  • make ui-test: Execute integration tests.

Contributing

We welcome contributions! Please see CONTRIBUTING.md for guidelines on how to get involved.

License

CycleOne is released under the GNU General Public License v3.0. See LICENSE for details.


Designed and developed by VoxDroid.
© 2026 VoxDroid. All rights reserved.