Tamer Köşe
Software engineer. Founder of App Branch.
Three-plus years of production React Native at INTIME, plus an indie mobile app studio shipping two apps so far — Astraea and Smart Scan X. AI as a force-multiplier across the stack — Next.js admin panels, Python automations, OpenAI chat and image flows — when the work calls for it.
About
I'm a software engineer. Three years at INTIME shipping production React Native apps across iOS, Android, and Huawei — phones, tablets, the lot — and owning the App Store, Play Store, and Huawei AppGallery release cycle.
In June 2025 I started App Branch, a small mobile app studio I run alongside the day job — iOS-first, with two apps live so far: Astraea (a PCOS & period tracker) and Smart Scan X (a portable scanner and PDF toolkit). Both are React Native + Expo. Each one is designed, built, submitted, and supported solo — product, code, marketing site, the lot.
React Native is the tech I'm deepest in. With AI as a force-multiplier I also ship adjacent work — Next.js + Supabase admin panels, Python automations, pnpm monorepos with web + admin, OpenAI chat and image flows, cron jobs — quickly enough that scope no longer caps what I can deliver.
Most of my time goes into the small things — the cadence of an animation, the wording of an empty state, whether a screen earns its place. I prefer shipping a few apps and looking after them carefully to chasing a portfolio, and I treat privacy and store-policy details as part of the design rather than an afterthought.
Experience
Stack: React Native, Expo, TypeScript, Supabase, OpenAI (chat + vision), App Store Connect
- •Founded App Branch in June 2025; operate the full studio cycle solo — product, code, App Store submissions, and marketing sites (appbranch.co, pcoshealth.app, documentscan.co).
- •Astraea (App Store) — PCOS-first cycle and symptom tracker with photo-based AI nutrition scoring. React Native + Expo + Supabase + OpenAI; anonymous-by-default, encrypted health-data architecture.
- •Smart Scan X (App Store) — document scanner and PDF toolkit (OCR, ID-card front/back PDF mode, AirPrint). React Native + Expo with community modules; no custom native code.
INTIME INFO SOFTWARE SOLUTIONS
Software Engineer / React Native Developer
Stack: React Native, TypeScript, WebRTC, Redux, Firebase, SQLite, Swift, Kotlin/Java, GitHub Actions
- •Develop and maintain the İntime İK super-app on production for App Store, Play Store, and Huawei AppGallery — HR, PDKS, expenses, tasks, surveys, and CRM modules.
- •Built native modules (Swift, Kotlin/Java) and integrated third-party SDKs for location, push, biometrics, and payment flows.
- •Implemented real-time messaging and 1:1 audio/video calling using WebRTC.
- •Optimise performance and reduce crash rates through systematic debugging, profiling, and refactoring.
- •Set up CI/CD for automated builds, tests, and triple-store deployments; mentor juniors and lead mobile-team code review.
WHOMII
React Native Developer
Stack: React Native, Expo, Firebase, Redux Toolkit, MongoDB, SQLite, Axios
- •Built and shipped the Whomii bilingual (TR/EN) psychology and mental-wellness app to App Store and Google Play.
- •Implemented complex state management for chat-style real-time interactions; integrated Firebase services and push notifications.
- •Integrated payment gateways and subscription management.
- •Worked closely with designers to deliver pixel-perfect mental-health onboarding flows.
Projects
Astraea — PCOS & Period Tracker
PCOS, finally understood.
App Branch's flagship iOS app — a PCOS-first health companion built for the ~10–15% of menstruating people whose bodies don't fit a generic period tracker.
My contribution
Designed and built end-to-end as the sole engineer: cycle and phase tracking, symptom logging with pattern recognition, a PCOS-aware AI assistant, and a Nutrition Scanner that scores meals for PCOS-friendliness from a single photo. Implemented anonymous-by-default authentication, encrypted health-data storage, and the App Store submission pipeline. Pure React Native + Expo (no custom native modules).
Tech stack
Platforms
Smart Scan X
Your iPhone, a full PDF toolkit.
Second App Branch product — a portable scanner and PDF workshop in one app. Scan, OCR, merge, split, and print straight from iOS.
My contribution
Designed and developed end-to-end as the sole engineer. Built the document-scanning pipeline with edge detection and filters, ID-card front/back PDF mode, OCR text extraction, PDF merge/split utilities, and direct AirPrint integration. Pure React Native + Expo with community modules — no custom native code.