Martin Gratzer

Projects

A selection of things I’ve built over 20+ years, from apps used by millions to side projects I’m tinkering with today.

Highlights

iTranslate Converse

Apple Design Award 2017 | watchOS

Part of the team that built iTranslate Converse for watchOS, a real-time conversation translation app that Apple recognized for outstanding design and innovation. One of those rare projects where everything clicked.

MindMeister & MeisterTask

7M+ / 10M+ users | iOS, macOS, watchOS

Shaped the mobile foundation for Meister’s productivity suite from 2010 through today. Built MindMeister’s mobile apps over 11 years, then helped build and shape MeisterTask iOS/watchOS from its 2015 launch. Clean Architecture, offline-first sync, deep platform integration.

iTranslate Pro

50M+ downloads | iOS, Android, Mac

Mobile architecture for the flagship translation app. Worked across iOS, Android, Mac, and Apple Watch versions during iTranslate’s rapid growth phase (2017-2019).

Bitmovin Player SDK

Used by HBO | iOS

Kicked off SDK development and designed a hybrid native/web solution for video playback. The SDK powers video for major streaming platforms including HBO.

Side Projects

What I’m building in my spare time.

Colorburst

AI-powered coloring book generation. A production SaaS using Gemini 2.5 for the generation pipeline.

Stack: Bun, Hono, PostgreSQL, React 19, Google Gemini

HatchUI

Server-Driven UI component delivery for mobile apps. Exploring how to ship UI changes without app updates using Kotlin Multiplatform.

Stack: Kotlin Multiplatform, SwiftUI, Jetpack Compose, Bun, Hono, PostgreSQL, React 19

Meister MCP

MCP server giving AI agents programmatic access to MeisterTask, MindMeister, and MeisterNote. 27+ tools for AI integration. Built during my 20% time at Meister.

Stack: TypeScript, Node.js, GraphQL, MCP SDK

Helios

Solar monitoring app for tracking photovoltaic systems. Built with Swift 6 strict concurrency.

Stack: Swift 6, SwiftUI, Xcode Cloud

Selected Client Work

A few highlights from 23 clients over 20+ years of freelancing through topmind GmbH.

ProjectClientWhat I Did
JamesAlturosWhite-label tourism eCommerce app for DACH ski destinations. Full stack from concept to delivery.
SkilineAlturosComplete rewrite of legacy ski tracking app for iOS and Android.
StepsAppStepsAppLegacy modernization using strangler fig pattern on ancient Objective-C codebase.
Authenticator+Rocket AppsEnd-to-end 2FA and password manager with cross-device sync and encryption.
femSenseSteadySenseMedTech fertility tracking app with Bluetooth LE wearable integration.
SommercardZell am See-KaprunTourism guest card app across iOS, Android, watchOS, and wearOS with Rails backend.
SalesPadTIME MODE22-year client relationship. E-commerce, B2B shop, mobile POS.

Entrepreneurial Ventures

Mobile Subscription Management Platform

2017-2018

Built a platform for managing mobile app subscriptions across iOS and Android, essentially RevenueCat before RevenueCat existed. Didn’t achieve product-market fit, but RevenueCat later proved the market was real. The deep StoreKit and Google Play Billing expertise from this venture directly led to consulting work.

Startup Mentoring