Open for product collaborations

Building thoughtfulsoftware acrossApple platforms and web.

I'm Timo, I design and ship apps with a strong bias for clarity, performance, and clean interaction details.

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About

Developer with a product mindset.

I'm Timo, a solo developer from Germany working across iOS, macOS, and web. I like turning rough ideas into products with clear structure and calm, precise interfaces.

Start

Why I began

I started coding because I wanted to build tools people actually use. What began as curiosity became a daily craft.

Now

What I build

Native iOS and macOS apps, responsive web products, and focused utilities that solve specific workflows.

Focus

What I care about

Learning with the help of AI. I believe there is no better time to start than now.

Clear architecture, strong UI rhythm, thoughtful UX, and performance that stays reliable in real-world use.

Toolkit

Apple

SwiftSwiftUIXcode

Web

TypeScriptReactNext.jsNode.jsTailwind CSS

Claude CodeCodexGemini

Projects

Product work with strong technical foundations.

A selection of products I'm building, from vertical SaaS to native Apple apps.

Building

PDF Editor for Mac

A native macOS PDF editor powered by a custom-built Swift PDF engine — no C dependencies, full concurrency support.

SwiftSwiftUI

Two projects in one: a standalone PDF processing engine (parsing, text extraction, encryption, digital signatures, forms, OCR text writing, PDF/A export) and the macOS editor built on top of it. The engine handles low-level PDF manipulation while the app provides the UI — annotations, inline text editing, watermarks, batch processing, merge/split, and cloud storage integration. The engine is a pure Swift package with zero external dependencies.

Building

Pet Service Platform

A SaaS tool for pet sitting and dog walking businesses — scheduling, invoicing, client management, and visit reports in one place.

Next.jsTypeScriptPostgreSQL

Building

Wedding App

A native iOS app that gives couples a digital hub for their wedding — and their guests a way to engage before, during, and after the day.

SwiftSwiftUINext.js

Contact

Let's build something useful.

If you have an idea, product, or collaboration in mind, send a message. I'm especially interested in projects where design quality and technical depth both matter.

dev@leisengang.online

Email GitHub Instagram

GitHub activity

2,086 contributions in the last year