Summary
- Scope and integrations drive cost more than the number of screens.
- Compare proposals against the same brief and clear exclusions.
- Include accessibility, privacy and maintenance in the budget.
Start with the problem, not a feature list
Before seeking a quote, write down who will use the app, the one task they must complete and what success looks like. An internal booking tool and a consumer marketplace have very different security, support and operating costs even if both have “accounts and payments”.
What drives the cost?
A simple prototype with limited screens can cost roughly $10,000–40,000 in the US or £8,000–30,000 in the UK. A production app with accounts, integrations, payments and ongoing support can cost substantially more. These are planning ranges, not quotes: accessibility, security reviews, data migration, testing, platform fees and integrations can change the total dramatically.
Native, cross-platform or web?
Native iOS and Android can make sense for intensive device features or complex performance requirements, but separate builds add work. Cross-platform can share code between mobile platforms, with trade-offs around specialised features. A mobile web app may be enough when users do not need app-store distribution, offline access or native hardware. Ask teams to explain their choice against your requirements rather than selling you a technology first.
Compare proposals fairly
Give each supplier the same brief. Request a breakdown by discovery, design, build, testing and maintenance, plus ownership of source code and design files. Check what is excluded: hosting, third-party subscriptions, security testing, app-store accounts, changes after sign-off and support. Agree on milestone acceptance criteria and what happens if work is delayed.
For US projects, ask about state privacy rules where relevant; for UK projects, consider UK GDPR and accessibility obligations. Both markets have app-store policies and payment rules that can affect your plan. Have contracts reviewed before transferring sensitive customer data.
Keep the first release small
Launch the smallest version that proves the central task works, gather feedback, then fund the next phase. Budget for maintenance from day one; even a finished app needs updates.