How to Write an App Brief a Developer Can Actually Quote

"I want an app like Uber, but for dog walkers. How much?" Any developer who answers that with a number is guessing. The answer could be $15,000 or $250,000, depending on a dozen things the sentence doesn't say.

You don't need a 40-page specification to get a real estimate. You need a one-page app requirements document that answers the questions a developer will ask anyway. Below is the template I'd love every client to send, with an example filled in, so you can copy it and get quotes you can actually compare.

Key takeaways

• One page beats forty. A short brief that answers the right questions gets better estimates than a long document nobody reads.
• Describe users and jobs, not screens. "A studio owner adds next week's classes in five minutes" is more useful than "a schedule screen".
• Split features into three tiers: must have for launch, should have soon, and later. That's what makes scope negotiable.
• List integrations and constraints early. Payments, regions, existing systems and compliance change estimates more than screen counts.
• Give a date and a budget range. Developers can shape scope to fit them; hiding them only produces quotes that don't.

The one-page app brief template (copy this)

1. The product in two sentences. Who it's for and what it lets them do.

2. Users and roles. Each type of user and what they need to do. For example: customer, studio staff, studio owner, admin.

3. The core flow. The one path through the app that must work perfectly at launch, step by step.

4. Features in three tiers.

• Must have at launch: the features without which you wouldn't launch.
• Should have soon: useful within a few months.
• Later: nice ideas, explicitly not in the first version.

5. Platforms. iOS, Android, web app, admin dashboard. Which ones at launch?

6. Integrations. Payments (which providers and countries), maps, calendars, CRM, existing APIs, hardware.

7. Data and compliance. Personal data, health or financial data, regions (EU, US, Gulf, India), any certifications you need.

8. Content and design. Do you have a brand, designs or a design system? Who writes the copy? Who supplies photos and data?

9. Constraints. A fixed launch date, an event, investor demos, existing tech you must use.

10. Budget range and timeline. A range is fine. It lets the developer propose the best scope for the money.

11. How you'll measure success. The number that tells you the first version worked.

A filled-in example

From a brief like this, a developer can estimate within a useful range, suggest what to move between tiers to hit the date, and ask sharper questions on the first call.

From the field: This example is close to the kind of product I've built. Floey, a fitness booking platform in Kuwait, needed a consumer app, an app for gym staff and owners, a multi-tenant backend and Kuwaiti payment rails. Each of those lines would change an estimate on its own, which is why the brief should name them up front.

Mistakes that make briefs hard to quote

• Describing it as another app. "Like Uber" or "like Airbnb" imports features you don't need. Describe your users' job instead.
• Listing screens instead of outcomes. Screens are the developer's job. Outcomes are yours.
• No tiers. If everything is "must have", nothing can move to hit a date or budget.
• Hiding the budget. You'll get quotes for imaginary projects, at both extremes.
• Forgetting the back office. Someone has to manage users, refunds and content. Say who and how.
• Ignoring the regions. Payments, privacy rules and languages depend on where your users are.

Questions a good developer will ask you

If you want to get ahead of the first call, prepare short answers to these. They come up on almost every project:

• What happens at the edges? A class is cancelled after people paid. A user loses connection mid-payment. Two people book the last spot at the same moment.
• Who manages the data? Who adds classes, edits prices, issues refunds and answers support requests, and with what tool?
• What's the money flow? Who gets paid, when, in which currency, and who handles refunds and payouts?
• What must be true on day one? Real data, real payments, a real support email, a privacy policy and terms.
• What can wait? Anything on the "later" list you'd be happy to drop if the date is at risk.

Having these answers ready shortens the estimate process, and it often reveals scope you hadn't thought about before it turns into a surprise invoice.

What happens after you send it

A good developer will come back with questions, not just a price. Expect them to ask about edge cases (what if a class is cancelled after people paid?), about the admin side, and about what success looks like. Then you should get an estimate broken down by line item or milestone, with assumptions written out. If a reply has no questions and a single number, treat it with caution.

Turning the brief into user stories

Once the brief is agreed, a developer will usually break the core flow into user stories with acceptance criteria. You can start that yourself, and it sharpens any quote:

Acceptance criteria are what turn "done" from an opinion into a checklist, which is also how milestones get signed off without arguments.

FAQ

What should an app requirements document include?

At minimum: who the users are, the core flow, features split into launch, soon and later, platforms, integrations, data and compliance needs, design status, constraints, budget range, timeline and how you'll measure success. One or two pages is enough for an accurate estimate.

Do I need wireframes before contacting a developer?

No. Wireframes help, but a clear brief is more important. Many developers include design in the project, and they'll often suggest a simpler flow than the one you would have drawn. If you have sketches or apps you like, include them as references.

Should I share my budget with app developers?

Yes, as a range. It lets developers propose the best version of your product for that money, instead of guessing. You're not obliged to accept the first quote, and a range still leaves room to compare offers.

How detailed should an app brief be for an MVP?

Detailed about the core flow and the must-have tier, light on everything else. An MVP brief that spells out the single flow that must work, and explicitly lists what's not included, gets more accurate and cheaper estimates.

Next steps

If you've written a brief using this template, send it to me and I'll reply with questions, a scope and an estimate broken down by line item. Get in touch, or see how I work as a React Native developer.

Sources

• App Review Guidelines, Apple
• Developer Program Policy, Google Play
• Stripe documentation, Stripe