UI vs UX: what is the difference
UX is the logic of the app: which screens a person moves through, how many steps lead to the goal and where they are likely to get confused. UI is what they see and tap: colours, fonts, icons, buttons and how each element behaves in different states.
A beautiful interface with muddled logic looks expensive, yet customers still drop the order on step three. Solid logic wrapped in a careless look works, but it does not earn trust, especially when people are asked to enter card details.
In practice the two layers are not built strictly one after another. Sometimes a mockup shows that a planned flow is awkward on a real screen, and the logic has to be reworked.
The stages of mobile app design
Good work starts with questions, not drawing: who your customer is, what job they do in the app and which scenarios are the most frequent. For food delivery that is a repeat order, for a beauty salon it is booking a master, for an online shop it is paying through Click or Payme.
- Research and usage scenarios.
- Screen structure and the transitions between screens.
- A clickable prototype without final styling.
- Visual style: colours, typography, icons, element states.
- Testing with people who were not part of the project.
- Handoff to developers with sizes, spacing and component specs.
Small screens, Android and iOS
A phone is controlled by a thumb, so button size, tap areas and the placement of key actions within thumb reach all matter. A website is built for a mouse and a wide screen, and copying a web layout straight into an app usually makes it harder to use.
Android and iOS have different habits for navigation, system gestures and standard elements. The core of the design system often stays shared, while the differences sit in exactly those places.
For Uzbekistan, add local details: an interface in Uzbek and Russian, phone entry in the +998 format, an SMS code step, a clear choice of payment method and sensible behaviour on a weak connection outside the capital. These small things directly affect how many orders get completed.
How design affects your business
A clear interface reduces the share of people who leave halfway through a flow, for example because a checkout form is confusing. The more users reach the target action, the cheaper each lead becomes for the same ad budget in Instagram or Telegram.
A tidy visual style also builds trust: an app that looks careless feels less reliable even when it works properly. And intuitive logic lowers the load on support, with fewer questions like how to cancel an order.
What drives the cost of app design
There is no single price list, and that is normal: the cost comes from the scope of work. The main factor is the number of unique screens. The second is scenario complexity. Empty states, errors, loading and going back need separate attention, not just the happy path.
Next comes whether the design system is built from scratch or an existing set of components is adapted to your product. Depth of research, the number of revision rounds and whether you need source files and guidelines for your own team also matter. Ask for an estimate after the task has been reviewed, not for a number over the phone.
Common mistakes and where to start
The first mistake is moving a website design into an app without adapting it. The second is skipping the prototype and drawing the final look straight away: fixing a flow in a mockup takes hours, fixing it in finished code takes far longer. The third is not showing the interface to newcomers before launch, because the team knows its own product too well to notice unclear steps.
Before commissioning an app, ask honestly whether you need one now. Often a mobile-friendly website, a Telegram bot or a presence on Uzum and OLX solves the problem, and the app comes later once you have repeat customers. If you are unsure, the markdev team can help compare the options, including a turnkey website, and estimate what will pay off. Describe your task and we will discuss where to begin.
FAQ
What is the difference between UI and UX design?
UX is the logic of the user's path: scenarios, steps and transitions. UI is the visual layer of that logic: colours, fonts, buttons and icons. An app needs both.
How much does mobile app UI UX design cost?
There is no fixed price. It depends on the number of screens, scenario complexity, interface states and whether the design system is built from scratch. A realistic estimate is possible only after the task is reviewed.
Do I need separate designs for Android and iOS?
The foundation is usually shared, but navigation and system elements feel different on each platform, so some screens are adapted.
Do I need a prototype before development?
Yes. A clickable prototype lets you test the flow before any code is written, and changes at that stage cost far less than after development.
Can I skip the app altogether?
Sometimes. If customers arrive from Instagram or Telegram, you can start with a mobile-friendly site or a bot and return to the app once repeat customers appear.
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