Custom web apps that replace spreadsheets, paper and group chats
I build custom web apps for small and mid-sized businesses: client portals, order and status tools, internal workflows and apps your team installs on their phones (PWA). You get a written fixed price after a free call, and the code belongs to you once the final invoice is paid. Running costs for hosting, updates and security checks are part of the quote.
What it costs
No German VAT is charged (small business rule, § 19 UStG). Third-party platform or licence costs are shown upfront.
- Field service and trade businesses
- Logistics and transport companies
- Repair and workshop businesses
- B2B suppliers with client orders
- Marketplaces and booking platforms
What I build
- Client and status portals: clients place orders with photos, follow the status and download reports as PDF.
- Digital job folders: job lists, photos, signatures on the phone and handover reports as PDF.
- Internal tools that replace spreadsheets and paper forms, with an export to a spreadsheet.
- Apps with payments via Stripe, including marketplaces with Stripe Connect.
- PWAs: web apps your team installs on the home screen, without an app store.
Fixed price, and the code belongs to you
The first version gets a fixed price based on a written scope. The contract sets out the scope, price, payment stages and formal acceptance. Code, hosting and accounts run in your name, and you get handover documentation, so another developer could take over. Unlike with many no-code platforms, there is no fee per user. Changes outside the scope get their own quote before I start.
Built with AI tools, checked before handover
I build with AI coding tools, and I check what they produce. AI-generated code is not secure by default: a Cloud Security Alliance research note reports that 45% of AI-generated code samples failed security tests based on the OWASP standard. So every project includes automated scans of the code and its libraries, a test of the access rules and a careful check of login and permissions.
What I have built
- My own social app with a video feed, live streaming and a shop, available on the App Store and as a web app.
- My own live auction app with real-time bidding and payments via Stripe Connect, in closed beta.
- My own professional network in German, Russian and English, with its data hosted in Frankfurt.
- An invoice reminder system for a client with many incoming invoices, running on a monitored server in Germany.
How it works
- 01
Free call
We go through the process that runs on paper, spreadsheets or group chats today and what the app must do.
- 02
Written scope and fixed price
You get the scope, the price and the payment stages in writing. Work starts once you agree.
- 03
Build and test
I build the first version, your team tests it with real cases, and we do the formal acceptance.
- 04
Handover and operation
Code and accounts are in your name, and you get handover documentation. Hosting, updates and security checks then continue for a monthly fee agreed in the quote.
Frequently asked questions
How much does a custom web app cost?
It depends on the scope: how many workflows, users and integrations the app needs. After a free call, you get a written fixed price before any work starts, and the quote also lists the running costs for hosting and security. I charge no German VAT under the small business rule (§ 19 UStG).
How long does it take to build a web app?
That depends on the scope, so I don't put a number on this page. You get a schedule together with the written scope and the fixed price. Limiting the first version to the core workflow keeps it small, and further features follow once your team is using it.
Who owns the code?
You do. Code, hosting and accounts run in your name, the source code handover is written into the contract, and you get handover documentation so another developer can take over if needed.
Do I need a native app or is a web app enough?
For most business tools a web app is enough. It runs in any browser, installs on the home screen as a PWA and needs no app store review. If you need to be in the App Store, I build with React Native and Expo. Apple's developer program costs 99 USD a year. With a personal account your own name appears as the seller; an organization account requires a legal entity with a D-U-N-S number.
Do you build with AI tools?
Yes, and I check what they produce. Automated scans of the code and its libraries, a test of the access rules and a careful check of login and permissions are included in every quote.
Can the app connect to tools we already use?
Usually, yes, if the tool has an interface (API) or an export. Accounting software, CRMs, email and spreadsheets are common examples. I check your tools before I quote a fixed price.
Where is the app hosted?
In the EU by default, with a data processing agreement. If your clients or your sector need a specific location, we specify it in the scope.
Which time zone do you work in?
I'm based in Germany (CET). My evening hours overlap with the business day on the US East Coast. Calls with clients in Europe, Israel or the Gulf are scheduled in advance. Most coordination is done in writing, and I usually reply the same evening or the next business day.