Mobile app design: how to design an app that feels right on iOS and Android

There are two ways an app most often gets designed wrong. The first is the shrunken website: the same menu, the same long copy and the same forms, just narrower. The second is the copy: "we want something like the competitor’s app", without anyone asking whether your users have the same tasks. Both can look fine in a presentation and feel wrong in the hand. Good mobile app design starts with the few things users need to do quickly, again and again, with one thumb, on a phone that may have a poor signal.

What is mobile app design, and how does it differ from web design?

App design covers both UX, how the app works, and UI, how it looks. We explain the difference in a full guide to UX vs UI design. What makes apps special is the context: users have installed the app, are often logged in and come back many times. That means speed and familiarity weigh more than explaining and persuading. At the same time, the phone has capabilities a website only partly reaches, such as push notifications, the camera, Face ID and offline access.

How does the app design process work, step by step?

The step most often skipped is number five. A Figma prototype can be opened on a phone and feels almost like the real app, and five users reveal most of the big problems in an afternoon. Moving a button in a prototype is far cheaper than moving it in an app that is live in the App Store. We cover the difference between wireframes, mockups and prototypes in our guide to wireframe, mockup and prototype, and how to run the test in usability testing with five people.

Which design guidelines apply on iOS and Android?

Your designer should know the guidelines inside out, so you only need the main points. The benefit of following them is that users already know how the app works, because it behaves like every other app on their phone. We build apps in React Native, where one codebase covers both iOS and Android, and where many components such as date pickers, the keyboard and back behaviour follow the platform automatically. The design is therefore made once, with a few deliberate adjustments per platform.

Which navigation pattern suits your app?

Our view is simple: if the app has more than one main task, use a bottom tab bar with three to five tabs, and put the rest under a "More" or profile tab. The drawer is tempting because everything fits in it, which is exactly why it becomes the place where features are hidden and forgotten. Name the tabs with words users use themselves, and always show both an icon and a label.

What needs to be in place before app design starts?

• One sentence on who the app is for and which problem it solves.
• The 3–5 most important tasks users must be able to complete in version one.
• How you measure success: for example bookings, fewer calls or weekly active users.
• User types: customers, staff, administrators, and what each needs to do.
• Which systems the app must talk to, such as e-conomic, MobilePay or your own ERP.
• Whether you need login, payments, push notifications, the camera or offline access.
• Brand material: logo, colours, fonts, images and tone.
• Who on your side approves designs, and how quickly they can respond.

Which mobile app design mistakes do we see most often?

• Login first: users must create an account before they have seen what the app can do.
• Every permission at first launch: push, location and camera before there is a reason.
• No plan for a poor signal: screens that freeze and input that disappears.
• Fixed font sizes: the app breaks when users have set larger text in their phone settings.
• Copy not written for mobile: long paragraphs where one sentence would do.
• The admin side is forgotten: there is nowhere to fix data, answer customers or send messages.
• No empty states or error messages: only the "happy paths" are designed.

Onboarding and permissions

Ask for permissions at the moment they make sense. Ask for camera access when the user taps "scan receipt", and for push notifications when they have booked an appointment and want a reminder. Explain in one sentence what they get out of it before the system dialog appears. If the user says no, the app should still work, and it should be easy to turn the feature on later. The same goes for onboarding: three short screens that show the value are enough, and they should be skippable.

What does mobile app design cost?

These figures are for design alone, bought separately. The whole app typically costs DKK 50,000–150,000 for a simple app and DKK 150,000–500,000 for a medium-complexity one on the Danish market, and the design is part of that. An example: a service company wants an app where customers can book, move and pay for visits. That is three main tasks, one user type and an admin panel on the web. The design lands in the first row, and with us the whole solution including design and development fits one of our app packages from DKK 28,000 plus the monthly plan. See the full price picture in how much does an app cost.

Do you need a store app, or is a web app enough?

Before you design an app, it is worth asking whether users will install it. Customers who use you every week happily do. Customers who buy twice a year rarely do, and here a mobile-friendly web solution or a PWA can be a better first step. Staff install what they are asked to, so internal apps are often an obvious choice, especially when the camera or offline access is needed. We compare the options in web app vs native app. If you go for a store app, also read about App Store approval, because some design choices affect whether the app is approved.

How do we approach mobile app design at Ceptiv?

With us, the same senior team designs and builds the app, so what is drawn in Figma is what ends up in the user’s hand. We start with flows and wireframes with real copy, test a clickable prototype on the phone and then build in React Native for both iOS and Android. For Kirppu we built, among other things, a label app alongside stand booking and a renter panel, and tools like that need exactly the kind of simple, fast flows this guide is about. See how we work under React Native app development, or get a fixed price within 24 hours.