Micro-App Idea Builder

Most small apps stall before the first line of code, at the point where you have to decide what to build. I made the Micro-App Idea Builder for that moment. You want to build something small and useful with AI, and you do not yet know what.

What does the Micro-App Idea Builder do?

It is a free micro-app idea generator that works from three choices: who you want to help, what they need help with, and what a useful result looks like for them. From those three answers it builds a concept for a small interactive web app, then adds the pieces that usually get skipped before building starts.

There are 8 audiences, 9 problems and 6 types of result, which gives 432 combinations. If you are not sure where to begin, the Surprise me button picks one at random. I would use it a few times before choosing anything.

What you get from each idea

• A concept: a plain description of the app, who it is for and what it promises.
• Names to try: three working titles, so the idea stops being nameless.
• What the visitor leaves with: the answer, plan, score or template your app ends on.
• How it could work and the features to start with: the flow from first question to final result.
• A first version: three small steps to build, in order.
• A scope check: six yes or no questions that tell you whether the idea is small enough to build first, with a note on whether it can sit on free hosting.
• Questions for three real people: five interview questions to ask before you spend a weekend building.
• A build prompt: a ready-made prompt you can paste into Claude, ChatGPT or Claude Code to ask for the app as a single file.

You can save ideas, copy a share link that reopens the same idea, download the brief as a Markdown file or print it.

How it works

Choose your three answers and select Build my idea. The tool matches your choices to a set of problem types, such as a decision guide, a calculator, a planner, an assessment, a learning companion, a resource generator, a navigator, a tracker or a preparation coach. It then fills in the audience and the result you chose. The scope check starts with every box ticked, so untick the ones that are not true for your idea and the verdict updates.

Who is it for?

It is for anyone who wants to build a small tool with AI and needs a place to start: coaches, consultants, creators, small business owners and people who have never written code. You do not need a finished idea. A person and something they need to get done is enough.

What it cannot do

The ideas come from a fixed set of problem types written into the tool in advance, not from an AI model reading your mind. That keeps it free and private, and it also means the ideas are starting points. Two people who pick the same options see the same idea.

It does not research your market, check what already exists or tell you whether people will pay for what you build. It does not guarantee that an idea is commercially viable. The scope check is a quick guide, not a review of your project. Saved ideas live in your browser on the device you are using, so clearing your browser data removes them. Download the brief for anything you want to keep.

What to do next with your idea

1. Run the scope check and cut the idea back until most of the boxes are ticked.
2. Ask three people the five questions and write down their answers word for word.
3. Copy the build prompt, paste it into the AI tool you use and answer the questions it asks you.
4. Test the first version on your phone and on a laptop.
5. Publish it. A micro-app that is a single file can go online for free, and the step by step route is in How to Publish an AI-Built Micro-App for Free.

The page also has a launch checklist with eight steps, from the one-sentence promise to sharing it with one person who needs it. Your ticks are saved in your browser.

Your privacy

Your choices are worked out in your browser. Nothing you select is sent to a server or to an AI service, and there is no sign-up.

Frequently asked questions

Is it free, and does it use AI?

It is free, with no sign-up and no limit on how many ideas you build. AI was used to make it: ChatGPT wrote the first version and Claude extended it into what you see here. The tool does not call an AI service while you use it, though. The ideas are written into the page, which is why it is instant and why nothing you choose leaves your browser. The AI comes in at the build prompt. When you paste that into Claude, ChatGPT or Claude Code, you are using that tool under your own account, and any usage limits or charges are set by that provider.

I asked three people the questions. What am I looking for in their answers?

Look for what they already do about the problem. Someone who keeps a messy spreadsheet, asks a friend or pays for a clumsy workaround is showing you the problem costs them something. Someone who says the idea sounds nice but cannot describe the last time it came up is telling you something too. Pay most attention to specific moments, such as the last time they had to make that choice and what annoyed them about it. If two or three people describe the same annoying step, build the app around that step. If they all describe different problems, go back to the idea builder and pick a narrower audience.

My idea needs accounts, payments or saved data. Can I still use this?

Yes, but build it in two stages. A single-file app can store things in the visitor's own browser, which covers a tracker, a checklist or a saved result without any server. Accounts, payments and anything shared between people need a server and a database, and free static hosting cannot provide either. They also bring responsibilities, because you would be holding other people's personal data and need a privacy policy and a plan for looking after it. Start with the browser-only version, see whether anyone uses it, and add the server side only when people ask for it.

I pasted the build prompt into an AI tool. How do I know what it gives me is right?

Expect it to ask you questions first. The prompt tells it to, because it does not know your subject and will fill the gaps with generic wording if you let it. Save what it produces as a file called index.html and open it in your browser. If the app does calculations, check three or four results by hand. If it gives recommendations or scores, read every result category and ask whether you would say that to a real person in that situation. Try odd inputs too, such as empty fields, a very large number or a very long answer. The AI builds the structure quickly. The content, the logic and the judgement about what is safe to tell people are yours to check.