IV.

Apps.

What I have built and can build for you. Pin & Done and the PDF Nischenfinder. — Proof that I do what I preach.

iOS & Android Web-Apps Custom development
App One · since 2024

Pin & Done

pinanddone.app

My first creation. An app for homeowners who want to keep their building records in order — no binders, no Excel chaos, no constant searching between emails, WhatsApp and PDFs.

With Pin & Done, a pile of scattered documents turns into an organized digital building file — sorted with AI, searchable, and shareable anytime with architects, tradespeople or your insurer. A personal problem became a product that hundreds of homeowners rely on every day.

Building filePDF sortingAI taggingiOS · Android · Web
See case study →
Building file
Single-family home · Heilbronn-Süd · 2026
Structural calcArchitect · 12.04.2026
Electrical quoteElektro Müller · 18.04.2026
Construction schedule v3Architect · 22.04.2026
Insurance policyBuilder's liability
Idea Drop
20 niches · DE · AT · CH
Raised beds for total beginnersSelf-sufficiency · Trend ↑ · 30-day plan
Financial plan for female foundersFinance · high demand
Sleep training for your babyFamily · steady searches
Prompt → PDFready to copy · Claude · ChatGPT
App Two · since 2026

PDF Nischenfinder

pdf-nischenfinder.de

My newest creation — and a different animal. A web tool that uses real data to show which PDF guides are genuinely in demand right now across Germany, Austria and Switzerland. No more guessing what to write about.

Three steps from a blank page to a ready-to-sell PDF: pick a niche, get an Idea Drop with title, target audience, price and the reasoning behind the trend — and for every idea, a ready-made prompt to copy into Claude, ChatGPT or Gemini. One free trial run, no credit card.

Market data · DACH20 nichesPrompt → PDFWeb app
To the Nischenfinder →
Custom development

Have an idea for your own app? Let's build it.

I build apps for trades, clubs, small businesses and solo entrepreneurs — with AI features if you want them, always GDPR-compliant, always as equals.

01

From problem to app

We start with the pain point — not with technology. What costs you time every day? What annoys you most? That's where the concept comes from.

02

Small, honest, fast

First version in weeks, not months. Tested with real users, fine-tuned regularly. Flat rate, no castles in the air.

03

It's yours

You become the owner of your app — source code, data, brand. I'll support its operation if you'd like, but you decide where it goes from here.

Begin

Carrying an app idea around with you?

Tell me about it.

In a free call we'll find out whether it holds up.