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Why a price range says nothing about your project
When you ask how much an app costs, a range “from X to Y euros” tells you nothing about your project. Two apps with the same number of screens can have very different quotes, depending on choices that can be named one by one. A good quote names them, feature by feature, and prices separately what the app will cost each month once it is live.
We build web and mobile apps and we operate one: Challenge Us, a group challenge app that we built, live in the browser since 2 September 2026, with a single codebase for the web, iPhone and Android (React Native and Expo) and a Supabase back end with real time and server functions. What follows comes from what we learned building it and running it, and it is how we price our app development, which starts with a written scope of what the app does on day one.
What makes the development price vary
Accounts and permissions
An app without accounts (a catalogue, a calculator) is simple. As soon as there are accounts, you need sign-up, login, recovery of a lost account, account deletion, and often several roles (customer, staff member, administrator) with different access rules. Each role adds screens and, above all, rules to test: who can see what, and who must never see it.
Data shared in real time
If two people have to see the same piece of information update before their eyes (a shared counter, an activity feed, an availability), you need a real-time mechanism and rules to decide between two simultaneous changes.
From the field
In Challenge Us, the server dates each entry
Real time is the core of Challenge Us: the day of an entry is calculated there by the server, in each participant’s time zone, and not by the phone’s clock, which could backdate it.
Offline use
An app that has to work without a network (on a building site, in a warehouse, on the move) has to store data on the phone, then synchronise it when the network comes back without losing or duplicating anything. It is an expensive decision, to be taken only if the use really demands it.
Payments
Taking payments in the app means integrating a payment provider and handling refunds, failures and invoices.
Watch out
The stores’ in-app purchase rules change the business model
On the app stores, the sale of digital content is subject to the platforms’ in-app purchase rules. This point is clarified from the scoping stage.
Notifications
Alerting a user when something happens requires a sending service, per-user settings (and the option to switch them off), and rules to avoid swamping people. On iPhone, an installed web app can receive notifications from iOS 16.4, according to WebKit’s announcement of February 2023, provided it has been added to the home screen. An installable app can therefore notify its users without going through the app stores, as we explain in PWA or native app: what to choose for a business.
Integrations
Connecting the app to your CRM, your ERP, your invoicing tool: each integration depends on the quality of the other software’s API. A documented API connects quickly; software without an API requires workarounds. It is often the most uncertain line of a quote, and a good quote says so.
Publishing on the app stores
Publishing on the App Store and Google Play means preparing the listings, the screenshots and the privacy policy, responding to the stores’ reviewers, and meeting specific requirements (account deletion within the app, for example, which Apple demands).
Administration
You almost always need a screen for yourself: to see accounts, correct a piece of data, track usage. It is often forgotten in first quotes, and added later at full price.
What the app costs once it is live
This is the part that many pricing pages sum up with an annual maintenance percentage, with no detail. Yet a live app has precise monthly costs, starting with the database and the server. As an example, here is what Supabase’s pricing page showed in October 2026:
at most can be active on the Free plan
of inactivity pauses a project on the Free plan
a month: the starting price of the Pro plan, with daily backups kept for seven days
The Free plan includes no automatic backup. A business application does not run on a plan that can pause itself and backs up nothing.
On top of the database and the server come:
- Hosting of the web interface, often modest for an app served as static files.
- Emails (login codes, notifications) through a sending service, with sending limits to keep an eye on.
- The stores’ developer accounts: in October 2026, $99 per year of membership at Apple, according to the developer programme enrolment page, which states that the price may vary by region, and $25 once only at Google, according to Play Console help.
- Updates: new versions of the iOS and Android systems, of libraries, of store rules. An app that is never updated ends up no longer meeting the stores’ requirements.
Ask for these lines to appear in the quote, with an order of magnitude for your volume of users. They change with the success of the app, and that is normal.
What brings the price down without harming the result
- A written day-one scope. What the app does at launch, and what will wait. Overruns often come from features added along the way.
- A single codebase for all platforms. Developing separately for iPhone, Android and the web multiplies the work and the fixes. Challenge Us shares a single codebase across the three.
- An installable version first. Putting the app in the hands of real users before the stores lets you correct course early, while it is still cheap.
- Proven services rather than custom-built ones for authentication, the database and email sending.
Honest limits
A custom app is not always the right answer.
When custom development is not needed
Off-the-shelf software covers most of your need, and you can live with its choices: the subscription will cost less
Your need fits in a form and a shared spreadsheet: a well-made automation is sometimes enough
When custom development is justified
The way you work is your advantage
No tool respects the way you work
Where to start
Write down the day-one scope: what the app does at launch, for whom, and what will wait. Then ask for a quote that prices each of these decisions separately, with the monthly running costs alongside. For this scoping, our app development first delivers a written scope, then a version in the hands of your first users. The other choices in a project, from the PWA to publishing on the stores, are gathered in our Web and mobile apps section. And on what AI changes in writing code, our article on vibe coding separates a prototype put together in a few hours from a product that is maintained.
Frequently asked questions
How long does it take to develop an app?
It depends on the same decisions as the price: accounts, real time, offline use, integrations. A tight day-one scope makes it possible to put a first version in users’ hands within a few weeks, then move forward in versions. Count publication on the stores separately: its administrative steps, such as opening the developer accounts in the company’s name, can start from the first day of development.
How much does app maintenance cost?
Ask for a line-by-line costing rather than a percentage: hosting, database, email sending, store accounts, and an update budget to keep up with new versions of iOS, Android and the libraries. The first lines depend mainly on the number of users, the last on the pace of change you want.
Who owns my app’s code?
You should: the code, the database and the developer accounts must be in your name, and the contract must say so before signing. Also check that you receive the access to the hosting and to the services used. Without this, changing provider can mean republishing the app under another account.
Sources
- WebKit’s announcement of February 2023 (new tab)webkit.org
- Supabase’s pricing page (new tab)supabase.com
- Developer programme enrolment page (new tab)developer.apple.com
- Play Console help (new tab)support.google.com
Jim · founder of Brain Plus AI
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