I’m an iOS Developer who ships products end-to-end: from idea and UI design, through implementation to App Store release and ongoing iteration.
I have built and maintain multiple SwiftUI apps, including:
- PillMemo: Medication reminders with Core Data/CloudKit, notifications, in-app purchases, automated tests and CI with Xcode Cloud
- MedScan: AI-powered medicine analysis using GPT-4 Vision plus a backend and custom UI components
- AquaVibe: Journey to a more mindful, hydrated and emotionally balanced life, using State of Mind and HealthKit API to save mood, emotions and water intake
data - ShotDocu: Multi-page PDF creation from photos/scans using PDFKit and CloudKit
My work has real product and growth outcomes, including #1 and Top 10 rankings in the US for selected keywords (ASO).
I use proven architectures (MVVM/VIPER), focus on reliability (error handling, testing, clean code) and deliver critical features that must be stable (sync, payments, notifications).
I combine engineering with product thinking: analytics (TelemetryDeck/Mixpanel/Aptabase), data-driven decisions, and fast iteration without sacrificing quality.
If you need a solid MVP or want to improve and scale an existing iOS app, I deliver predictably and efficiently.
Language
Work Experience
Education
Qualifications
Industry Experience
- SwiftUI
- Core Data
- CloudKit
- User Notifications
- UICalendarView
- In-App Purchases
- TipKit
- WishKit
- Concurrency
- Error handling & alerts
- Onboarding
- PDF Generator
- Unit Tests
- UI Tests
- CI/CD (Xcode Cloud)
- Project organization (VOODO Architecture)
- Privacy Manifest
- Published in App Store (04/2024)
💊 PillMemo
PillMemo is an easy-to-use application that helps users remember to take their medicine 🏥
The application allows users to set reminders for different types of medicine and at different times of the day/week/month 📅
👨💻 Technology Used
🎥 PillMemo ‘in action’
🏆 My standout success is…
Distinguish to save pill data with and without notifications.
Sounds trivial, but the real challenge was to create functionality to save pill data in Core Data and be read correctly by app, where each pill needed to be unique. Why? Because earlier, every next pill was saved, but remembered with the same reference, for the same date, where for the same date can be taken more than one pill. Without this change, app crashed every time when I wanted to save new pill with the same exact date.
🧩 Entireness
Nevertheless, while creating this simple medicine reminder app, I have also included the following:
ℹ️ License
The PillMemo is the property of Marcin Jędrzejak. Unauthorized copying, distribution, or modification of this application is strictly prohibited.
®️ 2026 All rights reserved by Marcin Jędrzejak.
MedScan is an iOS app for identifying medications. Take a photo of a medication’s packaging, and the image recognition system suggests the medication. After scanning, it displays detailed information about the medication - name, dosage and potential side effects. It helps you quickly check basic information about the pills you find, increasing safety and confidence when taking the medication.
Simple app for creating multi-page PDFs from photos or scans. Lets you combine images, rearrange pages, and adjust file quality for easy sharing.
- SwiftUI
- HealthKit
- Charts
- UserNotifications
- WishKit
- StoreKit2, RevenueCat
- TelemetryDeck
- AVKit, AVFoundation
- Concurrency
- Error handling & alerts
- Text input validation
- Project organization - MVVM Architecture
- Published in App Store (09/2024)
😎💧 AquaVibe
Track your wellness journey with AquaVibe, your all-in-one companion for mood, emotion, and hydration tracking 😊💦
The application allows users to set up to 3 daily reminders for consistent tracking and visualize their well-being with beautiful, interactive charts 📈
👨💻 Technology Used
🎥 AquaVibe ‘in action’
🏆 My standout success is…
AquaVibe wac created from scratch to fully working iOS Application, during RevenueCat Ship-a-ton competition. AquaVibe won Participation Prize during in RevenueCat Ship-a-ton competition:
The most challenging part was to understand ‘State of Mind’ logic.
From the documentation and sample project, was not so easy justified, so I needed to do a lot of tests to check and understand, how such function in ‘State of Mind’ logic works (for example, how correctly develop function to fetch and save mood or emotions data to Apple HealthKit).
Also, ‘State of Mind’ logic is something completely new, starting from iOS 18, so not so much information was available on the Internet.
✅ Entireness
Nevertheless, while creating this mood and water intake reminder app, I have also included the following:
ℹ️ License
The AquaVibe is the property of Marcin Jędrzejak. Unauthorized copying, distribution, or modification of this application is strictly prohibited.
®️ 2026 All rights reserved by Marcin Jędrzejak.
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