How to Write an App Specification: Complete Guide for Founders

What is an App Specification?

An app specification (often called an RFQ or Request for Quote) is a comprehensive document that describes your app idea in detail. It serves as a blueprint for development agencies to understand your vision, provide accurate quotes, and build your app correctly.

Think of it as a contract between you and your development team. The more detailed and clear your spec, the better your chances of getting accurate quotes and avoiding costly misunderstandings.

Why You Need an App Specification

Many founders skip the spec-writing process, thinking they can explain their idea in a few discovery calls. However, this approach leads to:

Weeks of back-and-forth: Agencies need to ask dozens of questions to understand your vision
Inaccurate quotes: Without clear requirements, agencies either overestimate (to cover unknowns) or underestimate (and then charge more later)
Scope creep: Unclear boundaries lead to feature additions and budget overruns
Misaligned expectations: What you think is included might not match what the agency delivers

A well-written spec solves all these problems. It gives agencies everything they need to provide accurate quotes and sets clear expectations from day one.

Key Sections of an App Specification

1. Executive Summary

Start with a brief overview of your app. Include:

App name and tagline
Core value proposition (what problem does it solve?)
Target audience
Platform (web, iOS, Android, or all)

2. Features and Functionality

List all features your app needs. Be specific:

User authentication: Email/password, social login, two-factor authentication?
Core features: What can users do? Be detailed about each feature
Admin features: What management capabilities do you need?
Third-party integrations: Payment processors, analytics, email services, etc.

3. User Flows

Describe how users will navigate through your app. Include:

Registration and onboarding flow
Main user journeys (e.g., "User wants to create a project")
Error handling (what happens when something goes wrong?)

4. Technical Requirements

Specify your technical needs:

Platform: Web (React, Vue, etc.), iOS, Android, or cross-platform
Backend: Database requirements, API needs, server infrastructure
Performance: Expected user load, response time requirements
Security: Data protection, compliance requirements (GDPR, HIPAA, etc.)

5. Design Preferences

Describe your visual preferences:

Color scheme and branding
Typography preferences
Overall style (modern, minimalist, bold, etc.)
Reference designs or inspiration

6. Timeline and Budget

Provide context on:

Desired launch date
Budget range (if you have one)
Priority features (MVP vs. nice-to-have)

Common Mistakes to Avoid

Being too vague: "User management" isn't helpful. Specify what users can do, what data you collect, etc.
Skipping edge cases: What happens when a user deletes their account? What if payment fails?
Ignoring technical details: Even if you're not technical, include requirements like "must work on mobile" or "needs to handle 10,000 users"
Forgetting about maintenance: Apps need updates, bug fixes, and ongoing support

How to Get Started

Writing a comprehensive spec from scratch can take days or weeks. That's why we built AppSpark—an AI-powered wizard that helps you create a professional app specification in just 15 minutes.

Our wizard guides you through all the key sections, asks the right questions, and generates a polished RFQ document you can share with any development agency. Try it free—no credit card required.

Conclusion

A well-written app specification is one of the most valuable documents you can create for your project. It saves time, reduces costs, and ensures everyone is on the same page. Whether you write it yourself or use a tool like AppSpark, investing in a good spec will pay dividends throughout your development journey.