workspace/mobile-development.md

Table of Contents

• Spear Online — Flagship Dental Education Platform -- line 28
  • Key Metrics -- line 34
  • Technical Highlights -- line 41
• Spear Practice Solutions — Dental Practice Intelligence -- line 50
  • Key Metrics -- line 54
  • Technical Highlights -- line 59
• Dig — The Dog Person's Dating App -- line 66
  • Key Metrics -- line 72
  • Technical Highlights -- line 78
• Guided Mind — Wellness & Meditation App -- line 87
  • Key Metrics -- line 93
  • Technical Highlights -- line 99
• Bodhi Mind — Daily Meditation Practice -- line 107
  • Key Metrics -- line 113
  • Technical Highlights -- line 119
• ContactCapture — AI-Powered Business Card Scanner -- line 126
  • Technical Highlights -- line 130
• Mixify — AI Image/Video Generation Platform (Contract) -- line 139
  • Key Metrics -- line 143
  • Technical Highlights -- line 149
• Swift Packages -- line 156
  • ASimpleAuthKit -- line 158
  • ASimpleCameraKit -- line 166
  • ASimplePurchaseKit -- line 174
• CI/CD & DevOps for Mobile -- line 182

Spear Online — Flagship Dental Education Platform

App Store

Charles drove the architecture and implementation of Spear Education's flagship iOS application as primary developer and eventual team lead. The app provides on-demand continuing education for dental professionals with video streaming, offline downloads, progress tracking, and CE credit tracking.

Key Metrics

• 4.9 App Store rating from 740+ reviews
• 17-minute average session duration
• 30% reduction in customer churn through improved mobile experience
• Standardized core functionality across 5 company mobile applications

Technical Highlights

• Offline Download Engine: Complete system using URLSession background tasks with concurrent download management, progress tracking, user-configurable cellular settings, and local notifications
• Team Management System: "Assign to Team" feature with RESTful batch operations and GraphQL backend integration for team progress tracking
• Advanced Search: Multi-tabbed interface with dynamically-fetched categories from GraphQL API and iCloud-synced recent searches
• Customizable Home Screen: Reorderable content carousels with iCloud-synced preferences
• Rich Video Player: AVKit integration with Picture-in-Picture, variable playback speeds, and detailed analytics tracking
• Technology: Swift, UIKit, GraphQL (Apollo), REST (Alamofire), Core Data, AVKit, Firebase, Fastlane, GitHub Actions

Spear Practice Solutions — Dental Practice Intelligence

Charles engineered the core architecture and features of the SPS iOS application, a practice intelligence tool for dental teams providing daily scheduling, patient follow-up management, and integrated communication tools (Email, SMS, Call).

Key Metrics

• Well-received by early-adopter clients for design and workflow efficiency
• Established scalable architecture blueprint for future company mobile projects

Technical Highlights

• Patient Follow-up System: GraphQL mutations and queries for creating, assigning, and tracking follow-up tasks with optimistic UI updates
• Advanced Filtering Engine: Multi-faceted filtering with pre-built filters, provider filtering, and patient status sorting
• Automated CI/CD: Custom scripts for GraphQL schema download and Swift code generation from Apollo toolchain
• Technology: Swift, UIKit, GraphQL (Apollo), REST (Alamofire), Core Data, Firebase, Fastlane

Dig — The Dog Person's Dating App

App Demo

As CTO of Dig Dates, Inc., Charles architected and built the complete iOS dating application and its Firebase backend from the ground up.

Key Metrics

• 25K+ monthly active users, 3K+ daily active users
• 4.7-star App Store rating
• 3-minute average session duration

Technical Highlights

• Matching Engine: Multi-stage algorithm filtering by gender preferences, dog ownership, geographic proximity, and age range, orchestrated through Firebase Cloud Functions
• Real-Time Chat: Integrated ChatSDK with Firebase Realtime Database for thousands of concurrent conversations
• Multi-Provider Auth: Email, Phone, Facebook, and Google Sign-In with account linking and duplicate detection
• Content Moderation: Image management pipeline with administrative review system
• Android Launch: Directed outsourced team to achieve 100% feature parity within 2–3 months
• Technology: Swift, UIKit, Firebase (Firestore, Cloud Functions, Realtime Database, Auth, Storage), Alamofire, StoreKit, Fastlane

Guided Mind — Wellness & Meditation App

App Store

Charles architected and implemented the complete application from concept to App Store launch. The app provides a library of over 400 meditations from 9 professional guides with streaming, offline listening, and subscription management.

Key Metrics

• 295K+ total installs
• 100,000+ user sessions
• 4.7 App Store rating

Technical Highlights

• Content Delivery: Firebase Realtime Database for content synchronization, Firebase Storage for audio streaming, custom FirebaseToCoreData layer for real-time updates
• Offline System: Track downloading with disk space management and local playback
• Monetization: Multi-tier subscription model (monthly, annual, lifetime) with 14-day free trial via StoreKit
• Spanish Localization: UI elements and interface text localized for Spanish-speaking users
• Technology: Objective-C, UIKit, AVFoundation, Core Data, Firebase, StoreKit

Bodhi Mind — Daily Meditation Practice

App Store

A wellness application featuring "Sitting With Bodhi," a daily guided meditation series combining a ~10-minute guided track with a user-configurable silent timer. Includes a library of nearly 300 meditations by Bodhipaksa.

Key Metrics

• 100,000+ user sessions
• 13K+ first-time users
• 4.6 App Store rating

Technical Highlights

• Daily Meditation Engine: Complex state management synchronizing AVPlayer audio playback with custom timer for silent meditation portion, including background chime notifications
• Multi-Provider Auth: Firebase Auth with Email, Google, Facebook, and Apple Sign-In via FirebaseUI
• HealthKit Integration: Logging completed sessions to Apple Health as Mindful Minutes
• Technology: Objective-C, UIKit, AVFoundation, Firebase, StoreKit, HealthKit

ContactCapture — AI-Powered Business Card Scanner

Charles is architecting a SwiftUI-based iOS application for scanning and extracting contact information from images using a custom AI/ML backend built with FastAPI and DSPy.

Technical Highlights

• FlowCoordinator Pattern: Action protocol with concrete actions (ProcessScanAction, ShowReviewAction, FinalizeAndEscrowAction) for testable, decoupled workflows
• EscrowManager: Local persistence system preventing data loss on network failure, automatically re-queueing failed saves
• Privacy-First Architecture: All data-sharing opt-in by default, just-in-time permission requests, granular tiered privacy controls
• Accessibility: Dynamic Type scaling, VoiceOver support with contextual labels and hints
• Localization: Localizable.xcstrings with NSLocalizedString for multi-language readiness
• Technology: Swift, SwiftUI, AVFoundation, Contacts framework, Combine, Firebase, FastAPI/DSPy backend

Mixify — AI Image/Video Generation Platform (Contract)

Charles was contracted as an iOS developer for Mixify, an AI-powered creative platform for image and video generation using art styles, meme templates, and face-swap technology.

Key Metrics

• 314 commits over 3 months
• 90,000+ lines of code added, 22,000+ refactored/removed
• Video playback system handling concurrent initialization across 1–3 CPU cores

Technical Highlights

• Video Playback System: Semaphore-based throttling, memory leak fixes via weak reference patterns, automatic background/foreground lifecycle management, scroll freeze detection (>50ms blocks)
• Skeleton Loading: Diagonal shimmer animations with centralized SkeletonShimmerCoordinator and SkeletonConfigurable protocol for app-wide consistency
• ImageDisplayVC Refactor: Consolidated 3 separate view controllers into single reusable component using presenter pattern with view adapters
• Technology: Swift, UIKit, AVFoundation, AVKit, Kingfisher, Firebase, RevenueCat

Swift Packages

ASimpleAuthKit

GitHub

Production-ready Swift Package providing Firebase Authentication integration for SwiftUI applications. Handles Email/Password, Google Sign-In, Apple Sign-In, with biometric authentication (Face ID/Touch ID) support. Manages 7 critical authentication states with automated handling. Reduces authentication implementation time by 2–3 weeks per project.

Technology: Swift, SwiftUI, Firebase Auth, Google Sign-In SDK, Keychain Services, LocalAuthentication

ASimpleCameraKit

GitHub

Swift Package providing camera functionality with proper orientation handling, image processing, and SwiftUI integration. Solves the notoriously difficult iOS image EXIF orientation problem.

Technology: Swift, SwiftUI, AVFoundation, Core Image

ASimplePurchaseKit

GitHub

Lightweight StoreKit 2 wrapper with async/await API for fetching products, making purchases, checking entitlements, and managing transaction history. Supports subscriptions, non-consumables, consumables, and promotional offers (iOS 17.4+). Zero external dependencies.

Technology: Swift, SwiftUI, StoreKit 2, iOS 16.4+/macOS 13.3+

CI/CD & DevOps for Mobile

At Spear Education, Charles took full ownership of mobile DevOps infrastructure, architecting a complete CI/CD pipeline from the ground up:

• Reduced deployment from ~3 hours of manual effort to 15-minute automated workflow
• Managed 50+ builds per week across all iOS and tvOS projects
• Built interactive QA system with comment-triggered workflows generating download links and QR codes on PRs
• Implemented path-based triggers and dependency caching for monorepo management with XcodeGen
• Optimized self-hosted macOS runners with custom Ruby compilation and caching

Technology: Fastlane, GitHub Actions, XcodeGen, SwiftLint, Xcov, CocoaPods