[Haruharu] #1 Paid Productivity

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📌 Overview

• Project duration: February 2019 ~ Present

• Role: Planning, design, development, launch and overall operations (solo project)

• Release platforms: iOS (iPhone, iPad, Apple Watch)

• App Store link: https://apps.apple.com/kr/app/id1452035712

• Featured:

  1. Korea App Store Story

  2. China App Store Story

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🧩 Project introduction

'HaruHaru' is inspired by the traditional Korean school vacation timetable Circular timetable-based time management app. Available on iPhone, iPad, and Apple Watch, with automatic iCloud sync, widgets, and Apple Watch complications, providing a user experience that allows checking schedules without opening the app.

Actively utilizing the latest iOS technologies such as SwiftUI, CoreData, CloudKit, WidgetKit, and WatchKit with the goal of delivering the best user experience within the scope manageable by a single developer.

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🔧 Tech stack and architecture

• Programming language: Swift

• UI framework: SwiftUI + UIKit (mixed)

• Architecture: MVVM + Clean Architecture

• Local / Cloud data: CoreData + CloudKit (iCloud integration)

• Feature extensions:

  • WidgetKit: Countdown and timetable widgets

  • WatchKit + ClockKit: Apple Watch app + complications

  • CoreAnimation, CoreGraphics: Custom circular UI rendering

  • StoreKit: Feature restrictions based on in-app purchases

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🚀 Key features and implementation examples

1. Circular timetable UI

• Using CoreGraphics and CoreAnimation Direct implementation of a circular clock-style timetable UI

  • The circular timetable UI for Widget and Watch Extension is implemented separately using SwiftUI

public static func drawSegment(
    withArc arc: Arc,
    lineWidth: CGFloat = 0,
    mode: CGPathDrawingMode = .fillStroke,
    inContext context: CGContext
) {
    let circle = arc.circle
    let origin = circle.origin
        
    UIGraphicsPushContext(context)
    context.beginPath()
        
    context.setLineWidth(lineWidth)
    context.move(to: origin)
    context.addArc(
        center: origin,
        radius: circle.radius,
        startAngle: arc.startAngle,
        endAngle: arc.endAngle,
        clockwise: false
    )
    context.move(to: origin)
    context.drawPath(using: mode)
        
    UIGraphicsPopContext()
}
    

Implemented time-range input component using UIControl

Main screen view hierarchy

2. Provide UX tailored to device characteristics

• iPhone: Single view focused on the circular diagram → concentrated schedule checking

• iPad: Simultaneous list + circular diagram (Split View) → improved navigation and readability

• Tailored to device characteristics, differentiated UX design

iPhone main screen

iPad main screen - using SplitViewController

3. iCloud sync and multi-device support

• Through CoreData + CloudKit integration, automatic data synchronization across all devices supported

• Implemented sync failure and conflict resolution logic directly

4. Widgets and Apple Watch support

• With WidgetKit, timetable previews, countdowns, and various widgets implemented

• Implemented Apple Watch app + complication features using WatchKit + ClockKit

  • Watch complications are also implemented by integrating with WidgetKit.

iOS App Widget

Apple Watch Complication

5. Premium feature locking (IAP)

• Feature lock/unlock via in-app purchases

• Implemented user entitlement verification logic based on App Store receipts

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🎯 Achievements

• 2019 ~ 2024 Selected as App of the Day on Korea App Store

• 2024 Featured on China App Store Experience

• Maintained top ranks in the paid app category (up to #2)

• Over 5,000 user reviews

• Maintained a relatively high rating of 4.6 from user reviews

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🧠 Retrospective

• Experienced SwiftUI from early versions and adapted flexibly to ecosystem changes

• This became a driving force for continuous growth as a developer

  • Provided opportunities to try and learn iOS and Swift updates and architectural patterns early

• Gained practical experience with a wide range of iOS ecosystem technologies such as iCloud integration, WatchKit, and widgets

• As a solo developer, handled operations, design, and incorporating user feedback, experienced the entire product lifecycle