Web app development · Fixed price

Web app development for small businesses.

A web app is your own program in the browser: on computer, tablet and phone, nothing to install. If no off-the-shelf software fits, OsAI builds you one.

Request a draftFree 15-min intro call
Fixed price before startFixed timelineSource code at handover
survey · your-business
Example
Site surveyKraus family · Bathroom
  • Wall A2.40 m
  • Wall B1.85 m
  • Room height2.50 m
Wall area21.3 m²
Add photoCreate quote
Handover
  • All logins
  • Full source code
  • Runs in the browser, phones included

04Handover: you get every access and the source code.

A made-up example.
In context

When a custom web app is worth it.

A custom web app is worth it when a task comes up often and off-the-shelf software only handles it with workarounds. Otherwise standard software is usually better.

Off-the-shelf software is enough if …

  • your workflow is the usual one.
  • the tool already exists.
  • the licence costs less.

A custom web app is worth it if …

  • your rules are too specific.
  • spreadsheets and paper fill the gap.
  • customers should enter data.
Carpenter measuring a window recess and entering the measurements on a tablet
Illustrative image (AI)
Proof

Over 20 in-house apps and tools built.

Four of them, all live.

Go to the AI tools
Start screen of Roast My Website, an in-house OsAI application

Roast My Website

Reviews a website automatically, point by point.

Start screen of the AI Time Machine, an in-house OsAI application

AI Time Machine

Moves a photo into another decade with AI.

Start screen of Immo-Expo, an in-house OsAI application

Immo-Expo

Turns property data into a presentation page.

Start screen of Angebots-Blitz, an in-house OsAI application

Angebots-Blitz

Turns a few bullet points into a finished quote.

Examples

What in-house web apps handle day to day.

Built in-house, ready to try.

Voice note → quote

Angebots-Blitz

A voice note after the appointment becomes priced line items.

See the demo
Questions to project documents

Projekt-Akte

Project documents in one place, answers with source.

See the demo
Website review at the push of a button

Roast My Website

Enter an address, the app checks the site.

Try it yourself
Restaurant manager checking the staff rota on a tablet in the kitchen before service
Illustrative image (AI)
What that can be

One small tool that's missing in the business.

A calculator for your own pricing

A form instead of a spreadsheet.

A client area

Clients check their status themselves.

A handover checklist

Filled in on site, saved at once.

A quote flow

Clients fill it in, the quote calculates.

Fixed price

How your fixed price is set

You get your fixed price after the free 15-min intro call, before any work starts.

Free 15-min intro call

What cost and timeline depend on

  • Scope

    Views, forms, logins.

  • Connections

    Calendar, accounting, inventory.

  • AI features

    Build effort plus running AI costs.

  • Existing data

    Importing and tidying up.

Process

Five steps.

Each step is finished before the next one starts.

  1. Clarify the task

    What's in, what's out.

  2. See the draft

    The key screens as a draft, before the price is set.

  3. Set fixed price and timeline

    In writing, up front.

  4. Build and show

    You see progress along the way.

  5. Hand over access and source code

    Other developers can build on it too.

After handover

What you get at handover — and where the app runs.

Every access and the full source code, plus the right to use the web app for the agreed purpose.

More details

The app runs with a hosting provider, not on a computer in your office. Running costs for hosting, database and, where used, AI arise there; provider and server location are settled before the build, with an eye on GDPR where personal data is involved. Later requests are scoped like the first build: clarify the task, fixed price, build.

What's not included

Honestly bounded.

  • Running other systems outside the project.
  • Third-party inventory systems without an interface.
  • An app in the phone's app store.
FAQ

Frequent questions about web app development.

What's the difference between a web app and an app from the app store?

A web app runs in the browser on computer, tablet and phone, without installation. An app-store app has to be built separately for iPhone and Android, approved and installed. For tools inside a business a web app is usually enough — OsAI doesn't build app-store apps.

What do price and timeline depend on?

On scope: the number of views and forms, logins with their own permissions, connections to other programs, AI features and importing existing data. Price and timeline are set in writing before the build starts.

What do I get when the web app is handed over?

Every access and the full source code, plus the right to use the app for the agreed purpose. You can have the app developed further by OsAI or by someone else.

Can a web app use AI too?

Yes, where it helps the task: Angebots-Blitz turns a voice note into a quote, Projekt-Akte answers questions about documents with the source. If a workflow should just run in the background without its own interface, AI automation is the better fit.

How it works: live demosAI automationGet a website builtAI tools to tryHow your fixed price is setAll solutionsContact
Next step

Sketch your web app
with OsAI.

Request a draft, or talk for 15 minutes.

Request a draftFree 15-min intro call

Fixed price before start · Source code at handover