How is a mobile app made? From idea to the App Store
A mobile app idea usually starts as one sentence: “we should have an app too.” Getting from there to a published product takes several stages, and each of them affects both the timeline and the budget.
Here is the process in the order it really happens.
Stage 0 — Do you actually need an app?
The most important question, and the one most often skipped. A mobile app costs more than a website and requires ongoing maintenance — iOS and Android update every year, and the app has to keep up with them.
An app earns its place when:
- People use your product regularly — several times a week
- You need to send push notifications
- It has to work offline
- You need device capabilities: camera, GPS, sensors, Bluetooth
- Payments or a loyalty programme run inside the app
If the goal is simply to present information, a catalogue or contact details, a good responsive website does the same job without asking anyone to install anything.
Stage 1 — Defining requirements
This is where you write down what the app will do: who uses it, what screens exist, which features go into version one and which wait.
The most common mistake is cramming everything into the first release. The practical approach is an MVP — a minimum viable product that ships with the features delivering the core value, then grows based on real user feedback.
Stage 2 — Design (UX and UI)
UX comes first: screen order and user flow mapped out as simple diagrams. How many taps does it take someone to get from opening the app to their goal?
UI follows: the actual visual design — colours, type, icons, motion. This is where iOS and Android interface conventions have to be respected; the same screen should feel native on both.
Stage 3 — Choosing the technology
This decision drives both cost and long-term maintenance.
Native
Written separately in Swift for iOS and Kotlin for Android. It gives the best performance and full access to device capabilities, but it means two codebases — roughly twice the work.
Suited to heavy graphics, complex animation or apps that lean hard on the device.
Cross-platform
One codebase in React Native or Flutter runs on both platforms. It saves meaningful time and budget, and current versions perform perfectly well for most business apps.
For the large majority of business apps this is the practical choice, and it is what we use on most projects.
Stage 4 — Development
The work usually splits in two:
- Frontend — what the user sees: screens and interaction.
- Backend — server, database, user accounts, API. The app has to get its data from somewhere.
The app is built in increments, with a test build handed over at the end of each cycle — so you see problems as they arise rather than at the end.
Stage 5 — Testing
Testing is more than checking whether it runs. The areas that matter:
- Different screen sizes and older devices
- Weak connections and offline state
- Behaviour when permissions (camera, notifications, location) are declined
- Battery and memory use
- Preserving existing data across updates
Stage 6 — Publishing to the stores
This stage is separate from the engineering and usually takes longer than people expect.
App Store (Apple) — an Apple Developer account carries an annual fee. Review typically takes a few days and Apple can reject a submission: duplicate functionality, a missing privacy policy or no test account provided for review are common reasons.
Google Play — a one-off registration fee, and review is generally faster.
Both stores need: an app icon, screenshots, a description, a privacy policy page and a declaration of what data you collect.
Stage 7 — After launch
Reaching the store is not the end of the work:
- Tracking usage analytics
- Investigating crash reports
- Responding to user reviews
- Keeping up with new iOS and Android releases
That last one matters: an app that stops being updated starts misbehaving on new devices within a year or two and can be removed from the store.
How long does it take?
Two to three months is realistic for a simple app, four to six for something of moderate complexity. That covers design, development, testing and store submission.
What stretches timelines most: requirements changing mid-project, delays in backend integrations, and content (text and images) arriving late.
Getting started
If you have an app idea, the first step is not picking a technology — it is writing down, in one sentence, what problem it solves. Everything else follows from that.
Take a look at our mobile app development service or get in touch.